Role of 100S ribosomes in bacterial decay period.
Ribosomal proteins S10 and S2 were each fused with GFP to track the fates of these proteins in the stationary growth phase and the following decay period in Escherichia coli. The fused proteins localized mainly in the cytoplasm, and their amounts were proportional to the colony-forming unit. S10-GFP strains that lacked genes responsible for regulating 100S ribosomes and S2-GFP strain that was unable to form 100S both showed shortened stationary phases. This result indicates that these strains exhibit earlier death in the absence of 100S formation (S2-GFP, S10-GFP∆rmf and S10-GFP∆hpf) and breakdown (S10-GFP∆yfiA). Therefore, in addition to the mere presence of 100S, the correct timing of 100S formation and breakdown is required to maintain viability. We propose a model in which 100S acts as a tentative repository of ribosomes that are protected from degradation and provide a source of amino acids in later growth period.
Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kita-Ku, 603-8555, Kyoto, Japan.
Ksenia
K
Shcherbakova
Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kita-Ku, 603-8555, Kyoto, Japan.
Hideki
H
Nakayama
Faculty of Life Sciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kita-Ku, 603-8555, Kyoto, Japan.
Nobuo
N
Shimamoto
D000596:Amino Acids / Q000378:metabolism; D004926:Escherichia coli / Q000166:cytology* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D066329:Protein Aggregates; D059748:Proteolysis; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism*
D000596:Amino Acids; D029968:Escherichia coli Proteins; D066329:Protein Aggregates; D012269:Ribosomal Proteins; C029537:ribosomal protein S10; C030004:ribosomal protein S2; D049452:Green Fluorescent Proteins