Document Detail

Rifampicin region revisited. New rifampicin-resistant and streptolydigin-resistant mutants in the beta subunit of Escherichia coli RNA polymerase.
MedLine Citation:
PMID:  8325861     Owner:  NLM     Status:  MEDLINE    
Mutations to rifampicin resistance (RifR) in Escherichia coli alter the beta subunit of RNA polymerase (RNAP). A series of new point RifR mutations was isolated with the aid of random polymerase chain reaction-mediated mutagenesis followed by selection on rifampicin (Rif). All of the new RifR mutants, including changes in two novel positions, fell into the two principal clusters previously identified in the middle section of beta. Disruption of the spacer between the two clusters with deletions and insertions led to RNAP that was functional and sensitive to Rif in vitro, indicating that the spacer is not directly involved in Rif binding. However, most of the spacer mutants were strongly resistant to streptolydigin, suggesting that this area is involved in the binding of streptolydigin. An insertion of six consecutive histidines into the spacer was constructed that could be used to anchor RNAP on a Nichelate matrix without the loss of enzymatic activity, indicating that this region is looped out of the RNAP molecule.
K Severinov; M Soushko; A Goldfarb; V Nikiforov
Publication Detail:
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.    
Journal Detail:
Title:  The Journal of biological chemistry     Volume:  268     ISSN:  0021-9258     ISO Abbreviation:  J. Biol. Chem.     Publication Date:  1993 Jul 
Date Detail:
Created Date:  1993-08-12     Completed Date:  1993-08-12     Revised Date:  2007-11-14    
Medline Journal Info:
Nlm Unique ID:  2985121R     Medline TA:  J Biol Chem     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  14820-5     Citation Subset:  IM    
Institute of Molecular Genetics, Russian Academy of Sciences, Moscow.
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MeSH Terms
Amino Acid Sequence
Anti-Bacterial Agents / pharmacology*
Base Sequence
DNA, Single-Stranded
DNA-Directed RNA Polymerases / genetics*,  metabolism
Drug Resistance, Microbial / genetics
Escherichia coli / drug effects*,  enzymology,  genetics
Molecular Sequence Data
Mutagenesis, Insertional
Mutagenesis, Site-Directed
Rifampin / pharmacology*
Sequence Alignment
Sequence Deletion
Transcription, Genetic
Grant Support
Reg. No./Substance:
0/Aminoglycosides; 0/Anti-Bacterial Agents; 0/DNA, Single-Stranded; 13292-46-1/Rifampin; 7229-50-7/streptolydigin; EC RNA Polymerases

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