scholarly journals The Revisited Genome of Bacillus subtilis Bacteriophage SPP1

Viruses ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 705 ◽  
Author(s):  
Lia M. Godinho ◽  
Mehdi El Sadek Fadel ◽  
Céline Monniot ◽  
Lina Jakutyte ◽  
Isabelle Auzat ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Dna Replication ◽  
Molecular Mechanisms ◽  
Replication Proteins ◽  
Particle Assembly ◽  
Multiplication Process ◽  
Viral Particles ◽  
Late Transcription ◽  
Transcriptional Units ◽  
Subtilis Bacteriophage

Bacillus subtilis bacteriophage SPP1 is a lytic siphovirus first described 50 years ago [1]. Its complete DNA sequence was reported in 1997 [2]. Here we present an updated annotation of the 44,016 bp SPP1 genome and its correlation to different steps of the viral multiplication process. Five early polycistronic transcriptional units encode phage DNA replication proteins and lysis functions together with less characterized, mostly non-essential, functions. Late transcription drives synthesis of proteins necessary for SPP1 viral particles assembly and for cell lysis, together with a short set of proteins of unknown function. The extensive genetic, biochemical and structural biology studies on the molecular mechanisms of SPP1 DNA replication and phage particle assembly rendered it a model system for tailed phages research. We propose SPP1 as the reference species for a new SPP1-like viruses genus of the Siphoviridae family.

scholarly journals Diversity and redundancy in bacterial chromosome segregation mechanisms

2005 ◽  
Vol 360 (1455) ◽  
pp. 497-505 ◽  
Author(s):  
Jeff Errington ◽  
Heath Murray ◽  
Ling Juan Wu
Keyword(s):  
Bacillus Subtilis ◽  
Dna Replication ◽  
Chromosome Segregation ◽  
Spatial Organization ◽  
Molecular Mechanisms ◽  
Chromosome Condensation ◽  
Bacterial Cells ◽  
Bacterial Chromosomes ◽  
Cell Organization ◽  
High Level

Bacterial cells are much smaller and have a much simpler overall structure and organization than eukaryotes. Several prominent differences in cell organization are relevant to the mechanisms of chromosome segregation, particularly the lack of an overt chromosome condensation/decondensation cycle and the lack of a microtubule-based spindle. Although bacterial chromosomes have a rather dispersed appearance, they nevertheless have an underlying high level of spatial organization. During the DNA replication cycle, early replicated ( oriC ) regions are localized towards the cell poles, whereas the late replicated terminus ( terC ) region is medially located. This spatial organization is thought to be driven by an active segregation mechanism that separates the sister chromosomes continuously as replication proceeds. Comparisons of various well-characterized bacteria suggest that the mechanisms of chromosome segregation are likely to be diverse, and that in many bacteria, multiple overlapping mechanisms may contribute to efficient segregation. One system in which the molecular mechanisms of chromosome segregation are beginning to be elucidated is that of sporulating cells of Bacillus subtilis . The key components of this system have been identified, and their functions are understood, in outline. Although this system appears to be specialized, most of the functions are conserved widely throughout the bacteria.

Use of Antibody to aid Visualization of Protein at the Termini of Bacteriophage Ø29 DNA

1980 ◽  
Vol 38 ◽  
pp. 540-541
Author(s):  
Dwight Anderson ◽  
Charlene Peterson ◽  
Gursaran Notani ◽  
Bernard Reilly
Keyword(s):  
Electron Microscopy ◽  
Bacillus Subtilis ◽  
Dna Synthesis ◽  
Restriction Endonuclease ◽  
Protein Complex ◽  
Protein Product ◽  
Viral Dna ◽  
Small Proteins ◽  
Antibody Labeling ◽  
Subtilis Bacteriophage

The protein product of cistron 3 of Bacillus subtilis bacteriophage Ø29 is essential for viral DNA synthesis and is covalently bound to the 5’-termini of the Ø29 DNA. When the DNA-protein complex is cleaved with a restriction endonuclease, the protein is bound to the two terminal fragments. The 28,000 dalton protein can be visualized by electron microscopy as a small dot and often is seen only when two ends are in apposition as in multimers or in glutaraldehyde-fixed aggregates. We sought to improve the visibility of these small proteins by use of antibody labeling.

Overlapping Roles of the Spindle Assembly and DNA Damage Checkpoints in the Cell-Cycle Response to Altered Chromosomes in Saccharomyces cerevisiae

Genetics ◽  
2002 ◽  
Vol 161 (2) ◽  
pp. 521-534
Author(s):  
Peter M Garber ◽  
Jasper Rine
Keyword(s):  
Dna Damage ◽  
Dna Replication ◽  
Spindle Checkpoint ◽  
Dna Lesions ◽  
Replication Proteins ◽  
Replication Checkpoint ◽  
Dna Damage Checkpoints ◽  
Dna Replication Checkpoint ◽  
Mcm Proteins ◽  
Stalled Replication Forks

Abstract The MAD2-dependent spindle checkpoint blocks anaphase until all chromosomes have achieved successful bipolar attachment to the mitotic spindle. The DNA damage and DNA replication checkpoints block anaphase in response to DNA lesions that may include single-stranded DNA and stalled replication forks. Many of the same conditions that activate the DNA damage and DNA replication checkpoints also activated the spindle checkpoint. The mad2Δ mutation partially relieved the arrest responses of cells to mutations affecting the replication proteins Mcm3p and Pol1p. Thus a previously unrecognized aspect of spindle checkpoint function may be to protect cells from defects in DNA replication. Furthermore, in cells lacking either the DNA damage or the DNA replication checkpoints, the spindle checkpoint contributed to the arrest responses of cells to the DNA-damaging agent methyl methanesulfonate, the replication inhibitor hydroxyurea, and mutations affecting Mcm2p and Orc2p. Thus the spindle checkpoint was sensitive to a wider range of chromosomal perturbations than previously recognized. Finally, the DNA replication checkpoint did not contribute to the arrests of cells in response to mutations affecting ORC, Mcm proteins, or DNA polymerase δ. Thus the specificity of this checkpoint may be more limited than previously recognized.

scholarly journals Phylogenetic analysis and secondary structure of the Bacillus subtilis bacteriophage RNA required for DNA packaging.

1990 ◽  
Vol 265 (36) ◽  
pp. 22365-22370
Author(s):  
S Bailey ◽  
J Wichitwechkarn ◽  
D Johnson ◽  
B E Reilly ◽  
D L Anderson ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Bacillus Subtilis ◽  
Secondary Structure ◽  
Dna Packaging ◽  
Subtilis Bacteriophage

scholarly journals Mutations in the Bacillus subtilis β Clamp That Separate Its Roles in DNA Replication from Mismatch Repair

2010 ◽  
Vol 192 (13) ◽  
pp. 3452-3463 ◽  
Author(s):  
Nicole M. Dupes ◽  
Brian W. Walsh ◽  
Andrew D. Klocko ◽  
Justin S. Lenhart ◽  
Heather L. Peterson ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Dna Replication ◽  
Mismatch Repair ◽  
Mutation Frequency ◽  
Elevated Temperatures ◽  
Temperature Sensitive ◽  
Mutant Form ◽  
Appreciable Effect ◽  
Missense Mutations ◽  
Dna Mismatch

ABSTRACT The β clamp is an essential replication sliding clamp required for processive DNA synthesis. The β clamp is also critical for several additional aspects of DNA metabolism, including DNA mismatch repair (MMR). The dnaN5 allele of Bacillus subtilis encodes a mutant form of β clamp containing the G73R substitution. Cells with the dnaN5 allele are temperature sensitive for growth due to a defect in DNA replication at 49°C, and they show an increase in mutation frequency caused by a partial defect in MMR at permissive temperatures. We selected for intragenic suppressors of dnaN5 that rescued viability at 49°C to determine if the DNA replication defect could be separated from the MMR defect. We isolated three intragenic suppressors of dnaN5 that restored growth at the nonpermissive temperature while maintaining an increase in mutation frequency. All three dnaN alleles encoded the G73R substitution along with one of three novel missense mutations. The missense mutations isolated were S22P, S181G, and E346K. Of these, S181G and E346K are located near the hydrophobic cleft of the β clamp, a common site occupied by proteins that bind the β clamp. Using several methods, we show that the increase in mutation frequency resulting from each dnaN allele is linked to a defect in MMR. Moreover, we found that S181G and E346K allowed growth at elevated temperatures and did not have an appreciable effect on mutation frequency when separated from G73R. Thus, we found that specific residue changes in the B. subtilis β clamp separate the role of the β clamp in DNA replication from its role in MMR.

Sign in / Sign up

Export Citation Format

Share Document