Biomedical subjects

Chuck Merryman

Publications and source records attributed to Chuck Merryman.

3 recordsLinked to original sources

PubMed2016

Design and synthesis of a minimal bacterial genome.

We used whole-genome design and complete chemical synthesis to minimize the 1079-kilobase pair synthetic genome of Mycoplasma mycoides JCVI-syn1.0. An initial design, based on collective knowledge of molecular biology combined with limited transposon mutagenesis data, failed to produce a viable cell. Improved transposon mutagenesis methods revealed a class of quasi-essential genes that are needed for robust growth, explaining the failure of our initial design. Three cycles of design, synthesis, and testing, with retention of quasi-essential genes, produced JCVI-syn3.0 (531 kilobase pairs, 473 genes), which has a genome smaller than that of any autonomously replicating cell found in nature. JCVI-syn3.0 retains almost all genes involved in the synthesis and processing of macromolecules. Unexpectedly, it also contains 149 genes with unknown biological functions. JCVI-syn3.0 is a versatile platform for investigating the core functions of life and for exploring whole-genome design.

Artificial Cells↗

PubMed2004

Transformation of aminoacyl tRNAs for the in vitro selection of "drug-like" molecules.

Evolutionary approaches are regularly used to isolate single molecules with desired activities from large populations of nucleic acids (approximately 10(15)). Several methods have also been developed to generate libraries of mRNA-encoded peptides and proteins for the in vitro selection of functional polypeptides. In principal, such mRNA encoding systems could be used with libraries of nonbiological polymers if the ribosome can be directed to polymerize tRNAs carrying unnatural amino acids. The fundamental problem is that current chemical aminoacylation systems cannot easily produce sufficient amounts of the numerous misacylated tRNAs required to synthesize a complex library of encoded polymers. Here, we show that bulk-aminoacylated tRNA can be transformed into N-monomethylated aminoacyl tRNA and translated. Because poly-N-methyl peptide backbones are refractory to proteases and are membrane permeable, our method provides an uncomplicated means of evolving novel drug candidates.

Amino Acids↗

PubMed2002

A bifunctional tRNA for in vitro selection.

In vitro selection is a powerful approach for generating novel aptamers and catalysts. Currently, several methods are being developed to extend this technique to proteins. In principle, selection methods could be applied to any library whose members can be replicated. Here, we describe a bifunctional tRNA that fuses translation products to their mRNAs. The utility of peptide-tRNA-mRNA fusions for in vitro selection was illustrated by the selective enrichment of tagged peptides-together with their mRNAs-by affinity chromatography. Our system can generate libraries larger than 10(11). Because library members can be copied and amplified, they provide a means for applying in vitro selection procedures to peptides and proteins. Furthermore, because the system is amenable to translation with misacylated tRNAs, a wide range of unusual monomers could be used to make libraries of nonstandard polymers for selection experiments.

Amino Acid Sequence↗