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Michael W W Adams

Publications and source records attributed to Michael W W Adams.

At least 19 recordsLinked to original sources
PubMed2024

Environmental stress mediates groundwater microbial community assembly.

Community assembly describes how different ecological processes shape microbial community composition and structure. How environmental factors impact community assembly remains elusive. Here we sampled microbial communities and >200 biogeochemical variables in groundwater at the Oak Ridge Field Research Center, a former nuclear waste disposal site, and developed a theoretical framework to conceptualize the relationships between community assembly processes and environmental stresses. We found that stochastic assembly processes were critical (>60% on average) in shaping community structure, but their relative importance decreased as stress increased. Dispersal limitation and 'drift' related to random birth and death had negative correlations with stresses, whereas the selection processes leading to dissimilar communities increased with stresses, primarily related to pH, cobalt and molybdenum. Assembly mechanisms also varied greatly among different phylogenetic groups. Our findings highlight the importance of microbial dispersal limitation and environmental heterogeneity in ecosystem restoration and management.

Phylogeny↗
PubMed2007

PF0610, a novel winged helix-turn-helix variant possessing a rubredoxin-like Zn ribbon motif from the hyperthermophilic archaeon, Pyrococcus furiosus.

PF0610, a protein from the hyperthermophile Pyrococcus furiosus, has homologues only in other archaeal species and in three species of Fe(III)-reducing bacteria. It is thought to have a helix-turn-helix (HTH) domain at the N-terminus and possesses two CXXC motifs characteristic of metal binding proteins. We have determined the solution structure of the Zn-bound protein using NMR. PF0610 is a novel winged helix-turn-helix (wHTH) protein with a rubredoxin-like Zn ribbon as its W1 segment. In addition, it possesses a large number of basic residues on its surface. Clusters of basic residues can be found on both helix H3 and the metal-binding loops of W1, suggesting that it might be a DNA-binding protein. Accordingly, gel shift assays using both linear and circular DNA showed that PF0610 does bind DNA, at least in a sequence-independent fashion. Modeling the PF0610-DNA interaction based on other wHTH protein-DNA structures revealed that besides helix H3, basic residues around the second CXXC motif in the metal-binding loop could make extensive contacts with DNA. However, the bulkiness of the W1 region implies that the DNA conformation may be distorted upon PF0610 binding. PF0610 is the first protein known to have a Zn ribbon-embedded wHTH fold and, as such, has potential roles both as a metal-dependent transcription regulator and as a component of the chromosome packing system in P. furiosus. The discovery of this novel structure represents the addition of another branch to the winged HTH protein family and could contribute to our understanding of transcription regulatory processes in P. furiosus.

Archaeal Proteins↗
PubMed2006

Comparing the electronic properties of the low-spin cyano-ferric [Fe(N4)(Cys)] active sites of superoxide reductase and p450cam using ENDOR spectroscopy and DFT calculations.

Superoxide reductase (SOR) and P450 enzymes contain similar [Fe(N)4(SCys)] active sites and, although they catalyze very different reactions, are proposed to involve analogous low-spin (hydro)peroxo-Fe(III) intermediates in their respective mechanisms that can be modeled by cyanide binding. The equatorial FeN4 ligation by four histidine ligands in CN-SOR and the heme in CN-P450cam is directly compared by 14N ENDOR, while the axial Fe-CN and Fe-S bonding is probed by 13C ENDOR of the cyanide ligand and 1Hbeta ENDOR measurements to determine the spin density delocalization onto the cysteine sulfur. There are small, but notable, differences in the bonding between Fe(III) and its ligands in the two enzymes. The ENDOR measurements are complemented by DFT computations that support the semiempirical equation used to compute spin densities on metal-coordinated cysteinyl and shed light on bonding changes as the Fe-C-N linkage bends. They further indicate that H bonds to the cysteinyl thiolate sulfur ligand reduce the spin density on the sulfur in both active sites to a degree that exceeds the difference induced by the alternative sets of "in-plane" nitrogen ligands.

Binding Sites↗
PubMed2006

Operon prediction in Pyrococcus furiosus.

Identification of operons in the hyperthermophilic archaeon Pyrococcus furiosus represents an important step to understanding the regulatory mechanisms that enable the organism to adapt and thrive in extreme environments. We have predicted operons in P.furiosus by combining the results from three existing algorithms using a neural network (NN). These algorithms use intergenic distances, phylogenetic profiles, functional categories and gene-order conservation in their operon prediction. Our method takes as inputs the confidence scores of the three programs, and outputs a prediction of whether adjacent genes on the same strand belong to the same operon. In addition, we have applied Gene Ontology (GO) and KEGG pathway information to improve the accuracy of our algorithm. The parameters of this NN predictor are trained on a subset of all experimentally verified operon gene pairs of Bacillus subtilis. It subsequently achieved 86.5% prediction accuracy when applied to a subset of gene pairs for Escherichia coli, which is substantially better than any of the three prediction programs. Using this new algorithm, we predicted 470 operons in the P.furiosus genome. Of these, 349 were validated using DNA microarray data.

Algorithms↗
PubMed2006

Observation of terahertz vibrations in Pyrococcus furiosus rubredoxin via impulsive coherent vibrational spectroscopy and nuclear resonance vibrational spectroscopy--interpretation by molecular mechanics.

We have used impulsive coherent vibrational spectroscopy (ICVS) to study the Fe(S-Cys)(4) site in oxidized rubredoxin (Rd) from Pyrococcus furiosus (Pf). In this experiment, a 15 fs visible laser pulse is used to coherently pump the sample to an excited electronic state, and a second <10 fs pulse is used to probe the change in transmission as a function of the time delay. PfRd was observed to relax to the ground state by a single exponential decay with time constants of approximately 255-275 fs. Superimposed on this relaxation are oscillations caused by coherent excitation of vibrational modes in both excited and ground electronic states. Fourier transformation reveals the frequencies of these modes. The strongest ICV mode with 570 nm excitation is the symmetric Fe-S stretching mode near 310 cm(-1), compared to 313 cm(-1) in the low temperature resonance Raman. If the rubredoxin is pumped at 520 nm, a set of strong bands occurs between 20 and 110 cm(-1). Finally, there is a mode at approximately 500 cm(-1) which is similar to features near 508 cm(-1) in blue Cu proteins that have been attributed to excited state vibrations. Normal mode analysis using 488 protein atoms and 558 waters gave calculated spectra that are in good agreement with previous nuclear resonance vibrational spectra (NRVS) results. The lowest frequency normal modes are identified as collective motions of the entire protein or large segments of polypeptide. Motion in these modes may affect the polar environment of the redox site and thus tune the electron transfer functions in rubredoxins.

Fourier Analysis↗
PubMed2006

Geometries and electronic structures of cyanide adducts of the non-heme iron active site of superoxide reductases: vibrational and ENDOR studies.

We have added cyanide to oxidized 1Fe and 2Fe superoxide reductase (SOR) as a surrogate for the putative ferric-(hydro)peroxo intermediate in the reaction of the enzymes with superoxide and have used vibrational and ENDOR spectroscopies to study the properties of the active site paramagnetic iron center. Addition of cyanide changes the active site iron center in oxidized SOR from rhombic high-spin ferric (S = 5/2) to axial-like low-spin ferric (S = 1/2). Low-temperature resonance Raman and ENDOR data show that the bound cyanide adopts three distinct conformations in Fe(III)-CN SOR. On the basis of 13CN, C15N, and 13C15N isotope shifts of the Fe-CN stretching/Fe-C-N bending modes, resonance Raman studies of 1Fe-SOR indicate one near-linear conformation (Fe-C-N angle approximately 175 degrees) and two distinct bent conformations (Fe-C-N angles <140 degrees). FTIR studies of 1Fe-SOR at ambient temperatures reveals three bound C-N stretching frequencies in the oxidized (ferric) state and one in the reduced (ferrous) state, indicating that the conformational heterogeneity in cyanide binding is a characteristic of the ferric state and is not caused by freezing-in of conformational substates at low temperature. 13C-ENDOR spectra for the 13CN-bound ferric active sites in both 1Fe- and 2Fe-SORs also show three well-resolved Fe-C-N conformations. Analysis of the 13C hyperfine tensors for the three substates of the 2Fe-SOR within a simple heuristic model for the Fe-C bonding gives values for the Fe-C-N angles in the three substates of ca. 123 degrees (C3) and 133 degrees (C2), taking a reference value from vibrational studies of 175 degrees (C1 species). Resonance Raman and ENDOR studies of SOR variants, in which the conserved glutamate and lysine residues in a flexible loop above the substrate binding pocket have been individually replaced by alanine, indicate that the side chains of these two residues are not involved in direct interaction with bound cyanide. The implications of these results for understanding the mechanism of SOR are discussed.

Binding Sites↗
PubMed2006

Transcriptional and biochemical analysis of starch metabolism in the hyperthermophilic archaeon Pyrococcus furiosus.

Pyrococcus furiosus utilizes starch and its degradation products, such as maltose, as primary carbon sources, but the pathways by which these alpha-glucans are processed have yet to be defined. For example, its genome contains genes proposed to encode five amylolytic enzymes (including a cyclodextrin glucanotransferase [CGTase] and amylopullulanase), as well as two transporters for maltose and maltodextrins (Mal-I and Mal-II), and a range of intracellular enzymes have been purified that reportedly metabolize maltodextrins and maltose. However, precisely which of these enzymes are involved in starch processing is not clear. In this study, starch metabolism in P. furiosus was examined by biochemical analyses in conjunction with global transcriptional response data for cells grown on a variety of glucans. In addition, DNA sequencing led to the correction of two key errors in the genome sequence, and these change the predicted properties of amylopullulanase (now designated PF1935*) and CGTase (PF0478*). Based on all of these data, a pathway is proposed that is specific for starch utilization that involves one transporter (Mal-II [PF1933 to PF1939]) and only three enzymes, amylopullulanase (PF1935*), 4-alpha-glucanotransferase (PF0272), and maltodextrin phosphorylase (PF1535). Their expression is upregulated on starch, and together they generate glucose and glucose-1-phosphate, which then feed into the novel glycolytic pathway of this organism. In addition, the results indicate that several hypothetical proteins encoded by three gene clusters are also involved in the transport and processing of alpha-glucan substrates by P. furiosus.

Archaeal Proteins↗
PubMed2005

Normal mode analysis of Pyrococcus furiosus rubredoxin via nuclear resonance vibrational spectroscopy (NRVS) and resonance raman spectroscopy.

We have used (57)Fe nuclear resonance vibrational spectroscopy (NRVS) to study the Fe(S(cys))(4) site in reduced and oxidized rubredoxin (Rd) from Pyrococcus furiosus (Pf). The oxidized form has also been investigated by resonance Raman spectroscopy. In the oxidized Rd NRVS, strong asymmetric Fe-S stretching modes are observed between 355 and 375 cm(-1); upon reduction these modes shift to 300-320 cm(-1). This is the first observation of Fe-S stretching modes in a reduced Rd. The peak in S-Fe-S bend mode intensity is at approximately 150 cm(-1) for the oxidized protein and only slightly lower in the reduced case. A third band occurs near 70 cm(-1) for both samples; this is assigned primarily as a collective motion of entire cysteine residues with respect to the central Fe. The (57)Fe partial vibrational density of states (PVDOS) were interpreted by normal mode analysis with optimization of Urey-Bradley force fields. The three main bands were qualitatively reproduced using a D(2)(d) Fe(SC)(4) model. A C(1) Fe(SCC)(4) model based on crystallographic coordinates was then used to simulate the splitting of the asymmetric stretching band into at least 3 components. Finally, a model employing complete cysteines and 2 additional neighboring atoms was used to reproduce the detailed structure of the PVDOS in the Fe-S stretch region. These results confirm the delocalization of the dynamic properties of the redox-active Fe site. Depending on the molecular model employed, the force constant K(Fe-S) for Fe-S stretching modes ranged from 1.24 to 1.32 mdyn/A. K(Fe-S) is clearly diminished in reduced Rd; values from approximately 0.89 to 1.00 mdyn/A were derived from different models. In contrast, in the final models the force constants for S-Fe-S bending motion, H(S-Fe-S), were 0.18 mdyn/A for oxidized Rd and 0.15 mdyn/A for reduced Rd. The NRVS technique demonstrates great promise for the observation and quantitative interpretation of the dynamical properties of Fe-S proteins.

Iron Isotopes↗
PubMed2005

Protein production and crystallization at SECSG -- an overview.

Using a high degree of automation, the Southeast Collaboratory for Structural Genomics (SECSG) has developed high throughput pipelines for protein production, and crystallization using a two-tiered approach. Primary, or tier-1, protein production focuses on producing proteins for members of large Pfam families that lack a representative structure in the Protein Data Bank. Target genomes are Pyrococcus furiosus and Caenorhabditis elegans. Selected human proteins are also under study. Tier-2 protein production, or target rescue, focuses on those tier-1 proteins, which either fail to crystallize or give poorly diffracting crystals. This two tier approach is more efficient since it allows the primary protein production groups to focus on the production of new targets while the tier-2 efforts focus on providing additional sample for further studies and modified protein for structure determination. Both efforts feed the SECSG high throughput crystallization pipeline, which is capable of screening over 40 proteins per week. Details of the various pipelines in use by the SECSG for protein production and crystallization, as well as some examples of target rescue are described.

Animals↗
PubMed2005

Comparison of small- and large-scale expression of selected Pyrococcus furiosus genes as an aid to high-throughput protein production.

As the natural extension of the genomic sequencing projects, the goal of the various world-wide Structural Genomics projects is development of techniques for high throughput (HTP) cloning, protein overexpression, purification and structural determination, with the ultimate goal of determining all possible protein structures. Rapid (small-scale) screening of potential expression clones under different growth conditions is presumed to be possible and a viable way to increase throughput of protein expression. In order to test the utility of screening for soluble, heterologous protein expression, we have compared the production of recombinant proteins on a small scale (1 ml cultures in 96-well plates) in Escherichia coli under two growth conditions [a rich medium and a defined (minimal) medium] using an enzyme-linked immunosorbent assay (ELISA) against the affinity tag, with the amount of recombinant protein produced during the large-scale (500 ml) growth of E. coli. The large-scale expression products were examined after a single step affinity purification by visualization on SDS-PAGE gels. Of the open reading frames that were successfully expressed on the 1 ml scale as judged by immunodetection, 80% of them successfully scaled-up to 500 ml in a rich medium and 81% of them scaled-up in a defined medium. This is significantly higher than would be expected by a randomly selected expression condition and validates the use of small-scale expression as a screening tool for more efficient protein production.

Bacterial Proteins↗
PubMed2005

In vitro reconstitution of an NADPH-dependent superoxide reduction pathway from Pyrococcus furiosus.

A scheme for the detoxification of superoxide in Pyrococcus furiosus has been previously proposed in which superoxide reductase (SOR) reduces (rather than dismutates) superoxide to hydrogen peroxide by using electrons from reduced rubredoxin (Rd). Rd is reduced with electrons from NAD(P)H by the enzyme NAD(P)H:rubredoxin oxidoreductase (NROR). The goal of the present work was to reconstitute this pathway in vitro using recombinant enzymes. While recombinant forms of SOR and Rd are available, the gene encoding P. furiosus NROR (PF1197) was found to be exceedingly toxic to Escherichia coli, and an active recombinant form (rNROR) was obtained via a fusion protein expression system, which produced an inactive form of NROR until cleavage. This allowed the complete pathway from NAD(P)H to the reduction of SOR via NROR and Rd to be reconstituted in vitro using recombinant proteins. rNROR is a 39.9-kDa protein whose sequence contains both flavin adenine dinucleotide (FAD)- and NAD(P)H-binding motifs, and it shares significant similarity with known and putative Rd-dependent oxidoreductases from several anaerobic bacteria, both mesophilic and hyperthermophilic. FAD was shown to be essential for activity in reconstitution assays and could not be replaced by flavin mononucleotide (FMN). The bound FAD has a midpoint potential of -173 mV at 23 degrees C (-193 mV at 80 degrees C). Like native NROR, the recombinant enzyme catalyzed the NADPH-dependent reduction of rubredoxin both at high (80 degrees C) and low (23 degrees C) temperatures, consistent with its proposed role in the superoxide reduction pathway. This is the first demonstration of in vitro superoxide reduction to hydrogen peroxide using NAD(P)H as the electron donor in an SOR-mediated pathway.

Amino Acid Sequence↗
PubMed2005

Cold shock of a hyperthermophilic archaeon: Pyrococcus furiosus exhibits multiple responses to a suboptimal growth temperature with a key role for membrane-bound glycoproteins.

The hyperthermophilic archaeon, Pyrococcus furiosus, was grown on maltose near its optimal growth temperature, 95 degrees C, and at the lower end of the temperature range for significant growth, 72 degrees C. In addition, cultures were shocked by rapidly dropping the temperature from 95 to 72 degrees C. This resulted in a 5-h lag phase, during which time little growth occurred. Transcriptional analyses using whole-genome DNA microarrays representing 2,065 open reading frames (ORFs) in the P. furiosus genome showed that cells undergo three very different responses at 72 degrees C: an early shock (1 to 2 h), a late shock (5 h), and an adapted response (occurring after many generations at 72 degrees C). Each response involved the up-regulation in the expression of more than 30 ORFs unique to that response. These included proteins involved in translation, solute transport, amino acid biosynthesis, and tungsten and intermediary carbon metabolism, as well as numerous conserved-hypothetical and/or membrane-associated proteins. Two major membrane proteins were evident after one-dimensional sodium dodecyl sulfate-gel analysis of cold-adapted cells, and staining revealed them to be glycoproteins. Their cold-induced expression evident from the DNA microarray analysis was confirmed by quantitative PCR. Termed CipA (PF0190) and CipB (PF1408), both appear to be solute-binding proteins. While the archaea do not contain members of the bacterial cold shock protein (Csp) family, they all contain homologs of CipA and CipB. These proteins are also related phylogenetically to some cold-responsive genes recently identified in certain bacteria. The Cip proteins may represent a general prokaryotic-type cold response mechanism that is present even in hyperthermophilic archaea.

Adaptation, Physiological↗
PubMed2005

Defining genes in the genome of the hyperthermophilic archaeon Pyrococcus furiosus: implications for all microbial genomes.

The original genome annotation of the hyperthermophilic archaeon Pyrococcus furiosus contained 2,065 open reading frames (ORFs). The genome was subsequently automatically annotated in two public databases by the Institute for Genomic Research (TIGR) and the National Center for Biotechnology Information (NCBI). Remarkably, more than 500 of the originally annotated ORFs differ in size in the two databases, many very significantly. For example, more than 170 of the predicted proteins differ at their N termini by more than 25 amino acids. Similar discrepancies were observed in the TIGR and NCBI databases with the other archaeal and bacterial genomes examined. In addition, the two databases contain 60 (NCBI) and 221 (TIGR) ORFs not present in the original annotation of P. furiosus. In the present study we have experimentally assessed the validity of 88 previously unannotated ORFs. Transcriptional analyses showed that 11 of 61 ORFs examined were expressed in P. furiosus when grown at either 95 or 72 degrees C. In addition, 7 of 54 ORFs examined yielded heat-stable recombinant proteins when they were expressed in Escherichia coli, although only one of the seven ORFs was expressed in P. furiosus under the growth conditions tested. It is concluded that the P. furiosus genome contains at least 17 ORFs not previously recognized in the original annotation. This study serves to highlight the discrepancies in the public databases and the problems of accurately defining the number and sizes of ORFs within any microbial genome.

Archaeal Proteins↗
PubMed2005

Metabolic and evolutionary relationships among Pyrococcus Species: genetic exchange within a hydrothermal vent environment.

Pyrococcus furiosus and Pyrococcus woesei grow optimally at temperatures near 100 degrees C and were isolated from the same shallow marine volcanic vent system. Hybridization of genomic DNA from P. woesei to a DNA microarray containing all 2,065 open reading frames (ORFs) annotated in the P. furiosus genome, in combination with PCR analysis, indicated that homologs of 105 ORFs present in P. furiosus are absent from the uncharacterized genome of P. woesei. Pulsed-field electrophoresis indicated that the sizes of the two genomes are comparable, and the results were consistent with the hypothesis that P. woesei lacks the 105 ORFs found in P. furiosus. The missing ORFs are present in P. furiosus mainly in clusters. These clusters include one cluster (Mal I, PF1737 to PF1751) involved in maltose metabolism and another cluster (PF0691 to PF0695) whose products are thought to remove toxic reactive nitrogen species. Accordingly, it was found that P. woesei, in contrast to P. furiosus, is unable to utilize maltose as a carbon source for growth, and the growth of P. woesei on starch was inhibited by addition of a nitric oxide generator. In P. furiosus the ORF clusters not present in P. woesei are bracketed by or are in the vicinity of insertion sequences or long clusters of tandem repeats (LCTRs). While the role of LCTRs in lateral gene transfer is not known, the Mal I cluster in P. furiosus is a composite transposon that undergoes replicative transposition. The same locus in P. woesei lacks any evidence of insertion activity, indicating that P. woesei is a sister or even the parent of P. furiosus. P. woesei may have acquired by lateral gene transfer more than 100 ORFs from other organisms living in the same thermophilic environment to produce the type strain of P. furiosus.

DNA Transposable Elements↗
PubMed2005

Characterization of a novel zinc-containing, lysine-specific aminopeptidase from the hyperthermophilic archaeon Pyrococcus furiosus.

Cell extracts of the proteolytic, hyperthermophilic archaeon Pyrococcus furiosus contain high specific activity (11 U/mg) of lysine aminopeptidase (KAP), as measured by the hydrolysis of L-lysyl-p-nitroanilide (Lys-pNA). The enzyme was purified by multistep chromatography. KAP is a homotetramer (38.2 kDa per subunit) and, as purified, contains 2.0 +/- 0.48 zinc atoms per subunit. Surprisingly, its activity was stimulated fourfold by the addition of Co2+ ions (0.2 mM). Optimal KAP activity with Lys-pNA as the substrate occurred at pH 8.0 and a temperature of 100 degrees C. The enzyme had a narrow substrate specificity with di-, tri-, and tetrapeptides, and it hydrolyzed only basic N-terminal residues at high rates. Mass spectroscopy analysis of the purified enzyme was used to identify, in the P. furiosus genome database, a gene (PF1861) that encodes a product corresponding to 346 amino acids. The recombinant protein containing a polyhistidine tag at the N terminus was produced in Escherichia coli and purified using affinity chromatography. Its properties, including molecular mass, metal ion dependence, and pH and temperature optima for catalysis, were indistinguishable from those of the native form, although the thermostability of the recombinant form was dramatically lower than that of the native enzyme (half-life of approximately 6 h at 100 degrees C). Based on its amino acid sequence, KAP is part of the M18 family of peptidases and represents the first prokaryotic member of this family. KAP is also the first lysine-specific aminopeptidase to be purified from an archaeon.

Amino Acid Sequence↗
PubMed2005

Posttranslational protein modification in Archaea.

One of the first hurdles to be negotiated in the postgenomic era involves the description of the entire protein content of the cell, the proteome. Such efforts are presently complicated by the various posttranslational modifications that proteins can experience, including glycosylation, lipid attachment, phosphorylation, methylation, disulfide bond formation, and proteolytic cleavage. Whereas these and other posttranslational protein modifications have been well characterized in Eucarya and Bacteria, posttranslational modification in Archaea has received far less attention. Although archaeal proteins can undergo posttranslational modifications reminiscent of what their eucaryal and bacterial counterparts experience, examination of archaeal posttranslational modification often reveals aspects not previously observed in the other two domains of life. In some cases, posttranslational modification allows a protein to survive the extreme conditions often encountered by Archaea. The various posttranslational modifications experienced by archaeal proteins, the molecular steps leading to these modifications, and the role played by posttranslational modification in Archaea form the focus of this review.

Archaea↗
PubMed2004

Bottlenecks and roadblocks in high-throughput XAS for structural genomics.

Structural and functional characterization of the entire protein complement (the proteome) of an organism can provide an infrastructure upon which questions about biological pathways and systems biology can be framed. The technology necessary to perform this proteome-level structural and functional characterization is under development in numerous structural genomics and functional genomics initiatives. Given the ubiquity of metal active sites in a proteome, it seems appropriate to ask whether comprehensive local structural characterization of metal sites within a proteome (metalloproteomics) is either a valid or obtainable goal. With a proteome-wide knowledge of the active-site structures of all metalloproteins, one could start to ask how metal insertion, cluster assembly and metalloprotein expression are affected by growth conditions or developmental status etc. High-throughput X-ray absorption spectroscopy (HTXAS) is being developed as a technology for investigating the metalloproteome. In creating a pipeline from genome to metalloproteome, several bottlenecks to high-throughput determination of metal-site structures must be overcome. For example, automation of arraying small samples for XAS examination must be invented, automation of rapid data collection of multiple low-volume low-concentration samples must be developed, automation of data reduction and analysis must be perfected. Discussed here are the promises and the pitfalls of HTXAS development, including the results of initial feasibility experiments.

Automation↗