PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 12441108

E.coli cell-cycle regulation by bacteriophage lambda.

Kirill Sergueev·Donald Court·Lucretia Reaves·Stuart Austin
View original source ↗Export metadata ↓

Abstract

We re-examined the old but surprising claim of Kourilsky and Knapp that transient expression of genes located downstream of the p(L) promoter of bacteriophage lambda can induce cell-cycle synchrony in a population of Escherichia coli cells. Although we were unable to reproduce a lasting synchrony, a cessation of division, followed by one or two fairly synchronous cell divisions was observed. This line up of the cell cycle was found to be due to two genetically separable events: a temporary block of cell division and, at the same time, a block to the initiation of new rounds of DNA replication. These blocks then release after about one mass doubling so that chromosome replication and cell division occur during a short time interval in all the cells in the population. The cell division block is a result of the transient expression of the lambda kil gene. The block to initiation of DNA replication requires a region that we term bin (blocks initiation) immediately upstream of the xis gene. The region consists of ea22 and ea8.5 and two small open reading frames (ORFs) that flank them. Deletion-substitution mutagenesis suggests that all four ORFs may be required for the initiation block. The ability of the phage to modify two aspects of the host cell cycle presumably reflects a stratagem that provides the phage with an advantage for lysogeny or lytic growth.

Explore related subjects

Bacterial ProteinsBacteriophage lambdaCell CycleCell DivisionChromosomes, BacterialCodon, InitiatorDNA PrimersDNA ReplicationDNA-Binding ProteinsEscherichia coliEscherichia coli ProteinsF FactorGene DeletionGene ExpressionLysogenyOpen Reading FramesPoint MutationRecombination, GeneticReplication OriginRepressor ProteinsViral ProteinsViral Regulatory and Accessory ProteinsJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Kirill Sergueev, Donald Court, Lucretia Reaves, Stuart Austin. 2002-11-22. E.coli cell-cycle regulation by bacteriophage lambda.. https://doi.org/10.1016/s0022-2836(02)01037-9

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2026

Prediction of bacterial protein-compound interactions with only positive samples.

MOTIVATION: Prediction of Compound-Protein Interactions (CPI) in bacteria is crucial to advance various pharmaceutical and chemical engineering fields, including biocatalysis, drug discovery, and industrial processing. However, current CPI models cannot be applied for bacterial CPI prediction due to the lack of curated negative interaction samples. RESULTS: We propose a novel Positive-Unlabeled (PU) learning framework, named BIN-PU, to address this limitation. BIN-PU generates pseudo positive and negative labels from known positive interaction data, enabling effective training of deep learning models for CPI prediction. We also propose a weighted positive loss function that weights to truly positive samples. We have validated BIN-PU coupled with multiple CPI backbone models, comparing the performance with the existing PU models using bacterial cytochrome P450 (CYP) data. Extensive experiments demonstrate the superiority of BIN-PU over the benchmark models in predicting CPIs with only truly positive samples. Furthermore, we have validated BIN-PU on additional bacterial proteins obtained from literature review, human CYP datasets, and uncurated data for its reproducibility. We have also validated the CPI prediction for the uncurated CYP data with biological and biophysical experiments. BIN-PU represents a significant advancement in CPI prediction for bacterial proteins, opening new possibilities for improving predictive models in related biological interaction tasks. AVAILABILITY AND IMPLEMENTATION: The source code and data are available at https://github.com/datax-lab/CYP.

Bacterial Proteins↗
PubMed2025

ComFB, a widespread family of c-di-NMP receptor proteins.

Cyclic dimeric-GMP (c-di-GMP) is a ubiquitous bacterial second messenger that regulates a variety of cellular processes, including motility, biofilm formation, secretion, cell cycle progression, and development, and also contributes to the virulence of many bacterial pathogens. While the genes encoding c-di-GMP cyclases and hydrolases are readily identifiable in microbial genomes, known c-di-GMP receptor domains are quite few, with only PilZ and MshEN broadly distributed across bacterial phyla. Recently, a new c-di-GMP receptor, named CdgR or ComFB, has been identified in cyanobacteria and shown to regulate cell size and natural competence. We demonstrated that CdgR proteins exhibit sequence and structural similarity to the Bacillus subtilis late competence development protein ComFB, a conserved protein of unknown function associated with bacterial competence. This prompted us to hypothesize that ComFB and ComFB-like proteins could also serve as c-di-GMP receptors. Here, we comprehensively investigated the ComFB protein family and demonstrated that ComFB proteins are evolutionarily widespread among bacteria and function as a novel family of c-di-GMP receptors. We showed that ComFB proteins from Gram-positive bacteria (B. subtilis, Thermoanaerobacter brockii) and Gram-negative pathogens (Vibrio cholerae, Treponema denticola) bind c-di-GMP with high affinity. Several ComFB proteins also bind cyclic di-adenosine monophosphate (c-di-AMP), suggesting that ComFB represents a widely distributed bacterial protein family with dual specificity for c-di-GMP and c-di-AMP. Our physiological studies further showed that ComFB plays vital roles in controlling motility in a c-di-GMP-dependent manner in two phylogenetically distant bacteria, B. subtilis and the gram-negative Shewanella oneidensis, attesting to the biological relevance of ComFB as a c-di-GMP binding protein.

Bacterial Proteins↗
PubMed2024

Dynamic structural determinants in bacterial microcompartment shells.

Bacterial microcompartments (BMCs) are polyhedral structures that segregate enzymatic cargo from the cytosol via encapsulation within a protein shell. Unlike other biological polyhedra, such as viral capsids and encapsulins, BMC shells can exhibit a highly advantageous structural and functional plasticity, conforming to a variety of anabolic (CO2 fixation in carboxysomes) and catabolic (nutrient assimilation in metabolosomes) roles. Consequently, understanding the subunit properties and associated protein-protein interaction processes that guide shell assembly and function is a necessary step to fully harness BMCs as modular, biotechnological nanomachines. Here, we describe the recent insights into the dynamics of structural features of the key BMC domain (Pfam00936)-containing proteins, which serve as a structural template for BMC-H and BMC-T shell building blocks.

Bacterial Proteins↗