Cell cycle arrest in Era GTPase mutants: a potential growth rate-regulated checkpoint in Escherichia coli.
Era is a low-molecular-weight GTPase essential for Escherichia coli viability. The gene encoding Era is found in the rnc operon, and the synthesis of both RNase III and Era increases with growth rate. Mutants that are partially defective in Era GTPase activity or that are reduced in the synthesis of wild-type Era become arrested in the cell cycle at the predivisional two-cell stage. The partially defective Era GTPase mutation (era1) suppresses several temperature-sensitive lethal alleles that affect chromosome replication and chromosome partitioning but not cell division. Our results suggest that Era plays an important role in cell cycle progression at a specific point in the cycle, after chromosome partitioning but before cytokinesis. Possible functions for Era in cell cycle progression and the initiation of cell division are discussed.
Britton
R A
RA
Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
Powell
B S
BS
Dasgupta
S
S
Sun
Q
Q
Margolin
W
W
Lupski
J R
JR
Court
D L
DL
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D002453:Cell Cycle / Q000502:physiology*; D002455:Cell Division / Q000235:genetics; D003598:Cytoskeletal Proteins; D004261:DNA Replication; D004251:DNA Transposable Elements; D004722:Endoribonucleases / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000502:physiology*; D029968:Escherichia coli Proteins; D020558:GTP Phosphohydrolases / Q000235:genetics* / Q000378:metabolism; D019204:GTP-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D016601:RNA-Binding Proteins; D043244:Ribonuclease III; D017386:Sequence Homology, Amino Acid; D013696:Temperature
D001426:Bacterial Proteins; D003598:Cytoskeletal Proteins; D004251:DNA Transposable Elements; D029968:Escherichia coli Proteins; C071525:FtsZ protein, Bacteria; D016601:RNA-Binding Proteins; C068027:era protein, E coli; D004722:Endoribonucleases; D043244:Ribonuclease III; C468366:ribonuclease III, E coli; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins