Isolation and partial characterization of Rhodopseudomonas sphaeroides mutants defective in the regulation of ribulose bisphosphate carboxylase/oxygenase.

Abstract

Several mutants of Rhodopseudomonas sphaeroides defective in the derepression of the enzyme ribulose 1,5-bisphosphate carboxylase have been isolated by using the unstable Tn5 vectors pJB4JI and pRK340. Transpositional insertion mutants obtained with pJB4JI were demonstrated to be incapable of increasing ribulose 1,5-bisphosphate carboxylase/oxygenase levels when grown on butyrate-bicarbonate medium or under conditions of carbon starvation, whereas the wild-type strain increased activity four- to eightfold. When the wild-type strain was starved for carbon in the presence of chloramphenicol, no derepression was observed. Crude extracts from mutant and wild-type strains had distinct and consistent differences in protein content as observed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Chromatographic evidence indicated that mutants were defective in the regulation of only one of the two forms of ribulose 1,5-bisphosphate carboxylase/oxygenase synthesized by R. sphaeroides.

• Authors: K E Weaver, F R Tabita
• Journal: Journal of bacteriology (J Bacteriol) Vol. 156 Issue 2 Pg. 507-15 (Nov 1983) ISSN: 0021-9193 [Print] United States
• PMID: 6313604 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S., Research Support, U.S. Gov't, P.H.S.)

Chemical References

• DNA Transposable Elements
• Ribulose-Bisphosphate Carboxylase

Topics

• Conjugation, Genetic
• DNA Transposable Elements
• Genetic Vectors
• Kinetics
• Mutation
• Plasmids
• Rhodobacter sphaeroides (enzymology, genetics, growth & development)
• Ribulose-Bisphosphate Carboxylase (genetics)
• Species Specificity