Biochemical and structural analyses reveal critical residues in δ subunit affecting its bindings to β′ subunit of Staphylococcus aureus RNA polymerase

2021 ◽  
Vol 545 ◽  
pp. 98-104
Author(s):  
Zhaozhu Lin ◽  
Fulin Wang ◽  
Zhuo Shang ◽  
Wei Lin
2015 ◽  
Vol 59 (7) ◽  
pp. 4215-4225 ◽  
Author(s):  
Miki Matsuo ◽  
Tomomi Hishinuma ◽  
Yuki Katayama ◽  
Keiichi Hiramatsu

ABSTRACTVarious mutations in therpoBgene, which encodes the RNA polymerase β subunit, are associated with increased vancomycin (VAN) resistance in vancomycin-intermediateStaphylococcus aureus(VISA) and heterogeneously VISA (hVISA) strains. We reported thatrpoBmutations are also linked to the expression of the recently found “slow VISA” (sVISA) phenotype (M. Saito, Y. Katayama, T. Hishinuma, A. Iwamoto, Y. Aiba, K Kuwahara-Arai, L. Cui, M. Matsuo, N. Aritaka, and K. Hiramatsu, Antimicrob Agents Chemother 58:5024–5035, 2014,http://dx.doi.org/10.1128/AAC.02470-13). Because RpoC and RpoB are components of RNA polymerase, we examined the effect of therpoC(P440L) mutation on the expression of the sVISA phenotype in the Mu3fdh2*V6-5 strain (V6-5), which was derived from a previously reported hVISA strain with the VISA phenotype. V6-5 had an extremely prolonged doubling time (DT) (72 min) and high vancomycin MIC (16 mg/liter). However, the phenotype of V6-5 was unstable, and the strain frequently reverted to hVISA with concomitant loss of low growth rate, cell wall thickness, and reduced autolysis. Whole-genome sequencing of phenotypic revertant strain V6-5-L1 and comparison with V6-5 revealed a second mutation, F562L, inrpoC. Introduction of the wild-type (WT)rpoCgene using a multicopy plasmid resolved the sVISA phenotype of V6-5, indicating that therpoC(P440L) mutant expressed the sVISA phenotype in hVISA. To investigate the mechanisms of resistance in the sVISA strain, we independently isolated an additional 10 revertants to hVISA and VISA. In subsequent whole-genome analysis, we identified compensatory mutations in the genes of three distinct functional categories: therpoCgene itself as regulatory mutations, peptidoglycan biosynthesis genes, andrelQ, which is involved in the stringent response. It appears that therpoC(P440L) mutation causes the sVISA phenotype by augmenting cell wall peptidoglycan synthesis and through the control of the stringent response.


2000 ◽  
Vol 44 (11) ◽  
pp. 3163-3166 ◽  
Author(s):  
Alexander O'Neill ◽  
Brunello Oliva ◽  
Christopher Storey ◽  
Anthony Hoyle ◽  
Colin Fishwick ◽  
...  

ABSTRACT A collection of rifampin-resistant mutants of Staphylococcus aureus with characterized RNA polymerase β-subunit (rpoB) gene mutations was cross-screened against a number of other RNA polymerase inhibitors to correlate susceptibility with specific rpoB genotypes. The rpoB mutants were cross-resistant to streptolydigin and sorangicin A. In contrast, thiolutin, holomycin, corallopyronin A, and ripostatin A retained activity against the rpoB mutants. The second group of inhibitors may be of interest as drug development candidates.


2013 ◽  
Vol 57 (10) ◽  
pp. 4861-4871 ◽  
Author(s):  
Yoshifumi Aiba ◽  
Yuki Katayama ◽  
Tomomi Hishinuma ◽  
Hiroko Murakami-Kuroda ◽  
Longzhu Cui ◽  
...  

ABSTRACTThree types of phenotypic expression of β-lactam resistance have been reported in methicillin-resistantStaphylococcus aureus(MRSA): heterogeneous, homogeneous, and Eagle-type resistance. Heterogeneous-to-homogeneous conversion of β-lactam resistance is postulated to be caused by a chromosomal mutation (chr*) in addition to the expression of themecAgene. Eagle-type resistance is a unique phenotype ofchr*occurring in pre-MRSA strain N315 whosemecAgene expression is strongly repressed by an intactmecIgene. We here report that certain mutations of therpoBgene, encoding the RNA polymerase β subunit, belong tochr*. We studied homogeneous MRSA (homo-MRSA) strain N315ΔIP-H5 (abbreviated as ΔIP-H5), which was obtained from hetero-MRSA strain N315ΔIP by selection with 8 mg/liter imipenem. Whole-genome sequencing of ΔIP-H5 revealed the presence of a unique mutation in therpoBgene,rpoB(N967I), causing the amino acid replacement of Asn by Ile at position 967 of RpoB. The effect of therpoB(N967I) mutation was confirmed by constructing a revertant H5rpoB(I967N) strain as well as an N315-derived mutant, N315rpoB(N967I). H5rpoB(I967N) regained the hetero-resistance phenotype, and the N315rpoB(N967I) strain showed an Eagle-type phenotype similar to that of the typical Eagle-type MRSA strain N315h4. Furthermore, subsequent whole-genome sequencing revealed that N315h4 also had a missense mutation ofrpoB(R644H). Introduction of therpoB(N967I) mutation was accompanied by decreased autolysis, prolonged doubling time, and tolerance to bactericidal concentrations of methicillin. We consider thatrpoBmutations are the major cause for heterogeneous-to-homogeneous phenotypic conversion of β-lactam resistance in MRSA strain N315 and its derived strains.


2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Anssi M. Malinen ◽  
Monali NandyMazumdar ◽  
Matti Turtola ◽  
Henri Malmi ◽  
Thadee Grocholski ◽  
...  
Keyword(s):  

1981 ◽  
Vol 9 (24) ◽  
pp. 6827-6840 ◽  
Author(s):  
C. Squires ◽  
A. Krainer ◽  
G. Barry ◽  
W.-F. Shen ◽  
C.L. Squires
Keyword(s):  

1981 ◽  
Vol 183 (1) ◽  
pp. 54-58 ◽  
Author(s):  
Ben A. Oostra ◽  
Klaas Kok ◽  
Adri J. Van Vliet ◽  
AB Geert ◽  
Max Gruber

1986 ◽  
Vol 203 (2) ◽  
pp. 265-268 ◽  
Author(s):  
Robert E. Glass ◽  
Steven T. Jones ◽  
Akira Ishihama

2008 ◽  
Vol 52 (7) ◽  
pp. 2313-2323 ◽  
Author(s):  
Gregory T. Robertson ◽  
Eric J. Bonventre ◽  
Timothy B. Doyle ◽  
Qun Du ◽  
Leonard Duncan ◽  
...  

ABSTRACT Rifamycins have proven efficacy in the treatment of persistent bacterial infections. However, the frequency with which bacteria develop resistance to rifamycin agents restricts their clinical use to antibiotic combination regimens. In a program directed toward the synthesis of rifamycins with a lower propensity to elicit resistance development, a series of compounds were prepared that covalently combine rifamycin and quinolone pharmacophores to form stable hybrid antibacterial agents. We describe mode-of-action studies with Staphylococcus aureus of CBR-2092, a novel hybrid that combines the rifamycin SV and 4H-4-oxo-quinolizine pharmacophores. In biochemical studies, CBR-2092 exhibited rifampin-like potency as an inhibitor of RNA polymerase, was an equipotent (balanced) inhibitor of DNA gyrase and DNA topoisomerase IV, and retained activity against a prevalent quinolone-resistant variant. Macromolecular biosynthesis studies confirmed that CBR-2092 has rifampin-like effects on RNA synthesis in rifampin-susceptible strains and quinolone-like effects on DNA synthesis in rifampin-resistant strains. Studies of mutant strains that exhibited reduced susceptibility to CBR-2092 further substantiated RNA polymerase as the primary cellular target of CBR-2092, with DNA gyrase and DNA topoisomerase IV being secondary and tertiary targets, respectively, in strains exhibiting preexisting rifampin resistance. In contrast to quinolone comparator agents, no strains with altered susceptibility to CBR-2092 were found to exhibit changes consistent with altered efflux properties. The combined data indicate that CBR-2092 may have potential utility in monotherapy for the treatment of persistent S. aureus infections.


Sign in / Sign up

Export Citation Format

Share Document