Biosynthetic regulation of individual proteins in relA + and relA strains of Escherichia coli during amino acid starvation

✍ Scribed by Reeh, Solvejg ;Pedersen, Steen ;Friesen, James D.

• Publisher: Springer
• Year: 1976
• Tongue: English
• Weight: 969 KB
• Volume: 149
• Category: Article
• ISSN: 0026-8925
• DOI: 10.1007/bf00268529

✦ Synopsis

An isogenic pair of Escherichia coli mutants (relA+ tufB valSts and relA1 tufB valSts) has been cultured at several temperatures to establish various degrees of limitation for valyl-tRNA synthetase. The biosynthetic rate of 16 identifiable proteins, most of which are components of the transcription and translation apparatus, was measured by pulse-labelling with [35S]-methionine, followed by protein separation using two-dimensional gel electrophoresis (O'Farrell, 1975). No single pattern of response to amino acid starvation of biosynthetic rate was observed. EF-Ts, L12 and S6 were found to be under strong stringent and relaxed regulation; EF-G, EF-Tu-A and S1 are under strong stringent, but weak relaxed regulation; EF-Tu-B, alpha, VRS, IRS and ARS are under week stringent and weak relaxed regulation; beta is under weak stringent regulation and does not respond at all to relaxed conditions; the biosynthetic rate of a protein called stringent starvation protein is strongly stimulated, relative to other proteins, in the starved stringent strain.