Escherichia coli ribosome-associated protein SRA, whose copy number increases during stationary phase

Citation
K. Izutsu et al., Escherichia coli ribosome-associated protein SRA, whose copy number increases during stationary phase, J BACT, 183(9), 2001, pp. 2765-2773
Citations number
51
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Microbiology
Journal title
JOURNAL OF BACTERIOLOGY
ISSN journal
0021-9193 → ACNP
Volume
183
Issue
9
Year of publication
2001
Pages
2765 - 2773
Database
ISI
SICI code
0021-9193(200105)183:9<2765:ECRPSW>2.0.ZU;2-Q
Abstract
Protein D has previously been demonstrated to be associated with Escherichi a coli ribosomes by the radical-free and highly reducing method of two-dime nsional polyacrylamide gel electrophoresis. In this study, we show that pro tein D is exclusively present in the 30S ribosomal subunit and that its gen e is located at 33.6 min on the E. coli genetic map, between ompC and sfcA. The gene consists of 45 codons, coding for a protein of 5,096 Da. The copy number of protein D per ribosomal particle varied during growth and increa sed from 0.1 in the exponential phase to 0.4 in the stationary phase. For t hese reasons, protein D was named SRA (stationary-phase-induced ribosome-as sociated) protein and its gene was named sra. The amount of SRA protein wit hin the cell was found to be controlled mainly at the transcriptional level : its transcription increased rapidly upon entry into the stationary phase and was partly dependent on an alternative sigma factor (sigma S). In addit ion, global regulators, such as factor inversion stimulation (FIS), integra tion host factor (IHF), cyclic AMP, and ppGpp, were found to play a role ei ther directly or indirectly in the transcription of sra in the stationary p hase.