Nucleotide sequence of the Staphylococcus aureus RNA polymerase rpoB gene and comparison of its predicted amino acid sequence with those of other bacteria

Aboshkiwa, Mohamed A; Rowland, Geoffrey C.; Coleman, G.

doi:10.1016/0167-4781(95)00054-k

Cited by 25 publications

(22 citation statements)

References 20 publications

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“…Previous reports based on work with various bacterial species has demonstrated that mutations in the rpoB gene (for the b-subunit of RNA polymerase) are responsible for the acquisition of resistance to rifampicin (Singer et al 1993;Aboshkiwa et al 1995;. In this study, a total of 12 different kinds of mutations were detected in a specific region, the socalled rif domain I (Fig.…”

Section: Discussionmentioning

confidence: 88%

A rifampicin resistance mutation in the rpoB gene confers ppGpp-independent antibiotic production in Streptomyces coelicolor A3(2)

Tozawa

Lai

et al. 2002

Mol Gen Genomics

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In Streptomyces coelicolor A3(2), deletion of relA or a specific mutation in rplK ( relC) results in an inability to synthesize ppGpp (guanosine 5'-diphosphate 3'-diphosphate) and impairs production of actinorhodin. We have found that certain rifampicin-resistant ( rif) mutants isolated from either relA or relC strains regain the ability to produce actinorhodin at the same level as the wild-type strain, although their capacity to synthesize ppGpp is unchanged. These rif mutants were found to have a missense mutation in the rpoB gene that encodes the RNA polymerase beta-subunit. This rpoB mutation was shown to be responsible for the observed changes in phenotype, as demonstrated by gene replacement experiments. Gene expression analysis revealed that the restoration of actinorhodin production in both relA and relC strains is accompanied by increased expression of the pathway-specific regulator gene actII-ORF4, which is normally decreased in the rel mutants. In addition to the restoration of antibiotic production, the rif mutants also exhibited a lower rate of RNA synthesis compared to the parental strain when grown in a rich medium, suggesting that these mutant RNA polymerases behave like "stringent" RNA polymerases. These results indicate that rif mutations can alter gene expression patterns independently of ppGpp. We propose that RNA polymerases carrying particular rif mutations in the beta-subunit can functionally mimic the modification induced by binding of ppGpp.

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Section: Discussionmentioning

confidence: 88%

A rifampicin resistance mutation in the rpoB gene confers ppGpp-independent antibiotic production in Streptomyces coelicolor A3(2)

Tozawa

Lai

et al. 2002

Mol Gen Genomics

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“…Previous studies of various bacteria, including S. coelicolor, demonstrated that mutations in the rpoB gene, which encodes the ␤-subunit of RNA polymerase, are responsible for the acquisition of resistance to rifampin (1,36,44). Almost all of the mutations are located in several conserved regions.…”

Section: Discussionmentioning

confidence: 99%

Activation of Antibiotic Biosynthesis by Specified Mutations in the rpoB Gene (Encoding the RNA Polymerase β Subunit) of Streptomyces lividans

2002

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We found that the biosynthesis of actinorhodin (Act), undecylprodigiosin (Red), and calcium-dependent antibiotic (CDA) are dramatically activated by introducing certain mutations into the rpoB gene that confer resistance to rifampin to Streptomyces lividans 66, which produces less or no antibiotics under normal growth conditions. Activation of Act and/or Red biosynthesis by inducing mutations in the rpoB gene was shown to be dependent on the mutation's position and the amino acid species substituted in the ␤-subunit of the RNA polymerase. Mutation analysis identified 15 different kinds of point mutations, which are located in region I, II, or III of the rpoB gene and, in addition, two novel mutations (deletion of nucleotides 1287 to 1289 and a double substitution at nucleotides 1309 and 1310) were also found. Western blot analyses and S1 mapping analyses demonstrated that the expression of actII-ORF4 and redD, which are pathway-specific regulatory genes for Act and Red, respectively, was activated in the mutants able to produce Act and Red. The ActIV-ORF1 protein (an enzyme for Act biosynthesis) and the RedD protein were produced just after the upregulation of ActII-ORF4 and RedZ, respectively. These results indicate that the mutation in the rpoB gene of S. lividans, resulting in the activation of Act and/or Red biosynthesis, functions at the transcription level by activating directly or indirectly the key regulatory genes, actII-ORF4 and redD. We propose that the mutated RNA polymerase may function by mimicking the ppGpp-bound form in activating the onset of secondary metabolism in Streptomyces.

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“…Rifampin acts by interacting specifically with the ␤ subunit of the bacterial RNA polymerase encoded by the rpoB gene (1). Rifampin resistance in Escherichia coli (13,22) and S. aureus is due to alterations in the target leading to a reduced affinity of the enzyme for the antibiotic (17).…”

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confidence: 99%

Characterization of Mutations in therpoBGene That Confer Rifampin Resistance inStaphylococcus aureus

Aubry‐Damon

Soussy

Courvalin

1998

Antimicrob Agents Chemother

206

122

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Mutations in the rifampin resistance-determining (Rif) regions of the rpoB gene of Staphylococcus aureus mutants obtained during therapy or in vitro were analyzed by gene amplification and sequencing. Each of the resistant clinical isolates, including five nonrelated clones and two strains isolated from the same patient, and of the 10 in vitro mutants had a single base pair change that resulted in an amino acid substitution in the ␤ subunit of RNA polymerase. Eight mutational changes at seven positions were found in cluster I of the central Rif region. Certain substitutions (His481/Tyr and Asp471/Tyr [S.aureus coordinates]) were present in several mutants. Substitutions Gln468/Arg, His481/Tyr, and Arg484/His, which conferred high-level rifampin resistance, were identical or in the same codon as those described in other bacterial genera, whereas Asp550/Gly has not been reported previously. Substitutions at codon 477 conferred high-or low-level resistance, depending on the nature of the new amino acid. The levels of resistance of in vivo and one-step in vitro mutants carrying identical mutations were similar, suggesting that no other resistance mechanism was present in the clinical isolates. On the basis of these data and the population distribution of more than 4,000 clinical S. aureus isolates, we propose <0.5 and >8 g/ml as new breakpoints for the clinical categorization of this species relative to rifampin.

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Nucleotide sequence of the Staphylococcus aureus RNA polymerase rpoB gene and comparison of its predicted amino acid sequence with those of other bacteria

Cited by 25 publications

References 20 publications

A rifampicin resistance mutation in the rpoB gene confers ppGpp-independent antibiotic production in Streptomyces coelicolor A3(2)

A rifampicin resistance mutation in the rpoB gene confers ppGpp-independent antibiotic production in Streptomyces coelicolor A3(2)

Activation of Antibiotic Biosynthesis by Specified Mutations in the rpoB Gene (Encoding the RNA Polymerase β Subunit) of Streptomyces lividans

Characterization of Mutations in therpoBGene That Confer Rifampin Resistance inStaphylococcus aureus

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