Cyanobacterial RNA polymerase genes rpoC1 and rpoC2 correspond to rpoC of Escherichia coli

Xie, Wen; Jäger, Karin; Potts, Malcolm

doi:10.1128/jb.171.4.1967-1973.1989

Cited by 57 publications

(33 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The genes are colinear with the rpoB and rpoC genes of E. coli, but homology to the P' subunit of E. coli is divided between two genes, rpoCI and rpoC2. The same split in the rpoC gene is present in the cyanobacterium N. commune UTEX 584 (47) and in plant chloroplasts (19,20,38). While the organization of the cyanobacterial and chloroplast rpoBCIC2 genes resembles the rpoBC operon of E. coli, the Anabaena and chloroplast genes do not lie distal to any ribosomal protein genes (3a, 19, 20).…”

Section: Resultsmentioning

confidence: 93%

See 1 more Smart Citation

Evolutionary relationships among eubacteria, cyanobacteria, and chloroplasts: evidence from the rpoC1 gene of Anabaena sp. strain PCC 7120

Bergsland

Haselkorn

1991

J Bacteriol

View full text Add to dashboard Cite

RNA polymerases of cyanobacteria contain a novel core subunit, y, which is absent from the RNA polymerases of other eubacteria. The genes encoding the three largest subunits of RNA polymerase, including y, have been isolated from the cyanobacterium Anabaena sp. strain PCC 7120. The genes are linked in the order rpoB, rpoCl, rpoC2 and encode the 1, y, and B' subunits, respectively. RNA polymerase in prokaryotes generally consists of a catalytic core of four subunits (W313'a2) and a dissociable sigma factor, which confers promoter specificity (7,16,44). The basic structure of the enzyme was believed to be the same in all eubacteria until the RNA polymerase of the filamentous cyanobacterium Anabaena sp. strain PCC 7120 was purified (37). The cyanobacterial core RNA polymerase was found to contain, in addition to a ,B, a ,3', and two a's, a novel core subunit of 70 kDa designated y, which is absent from the RNA polymerases of other eubacteria. Western immunoblotting with antiserum to -y has shown that a serologically related -y protein is present in over 30 different cyanobacteria, representing the five major taxonomic subgroups (4a, 36). Thus, the -y subunit is a common feature of cyanobacterial RNA polymerases.Anti--y serum cross-reacts with the Escherichia coli ' subunit protein, suggesting homology between these subunits (36). A region of DNA homologous to part of the E. coli gene encoding 3' (rpoC) has been isolated from another cyanobacterium, Nostoc commune UTEX 584 (47). Sequencing of this region showed that homology to E. coli rpoC is split between two linked genes, rpoCl and rpoC2, in the Nostoc DNA (47). The DNAs of several plant chloroplasts have likewise been found to contain regions of sequence homology with E. coli rpoC (19,20,30,38,39). In chloroplasts, the blocks of homology are also distributed between two genes, rpoCl and rpoC2. These genes are linked and are thought to encode the P' and ,B" subunits of chloroplast RNA polymerase, respectively.The exact subunit composition of chloroplast RNA polymerase is unclear. Spinach chloroplast RNA polymerase was found to contain seven prominent polypeptides, some of which were serologically related to subunits of the E. coli RNA polymerase (26). DNA sequences potentially encoding protein equivalents to the E. coli a and ,B subunits (rpoA and * Corresponding author. rpoB) have been found in chloroplast genomes, in addition to the rpoC homologs (19,20,30,39,40). In a few cases, these genes have been shown to be expressed in chloroplasts. The protein product of the rpoA gene has been identified in maize and pea chloroplasts (33,34 Isolation ofAnabaena sp. strain PCC 7120 RNA polymerase genes. The 2.8-and 2.3-kb EcoRI fragments containing parts of the E. coli rpoB and rpoC genes, respectively, were isolated from pGB218 (2), which was a gift from C. Squires. The fragments were labeled with [a-32P]dCTP (3,000 Ci/ mmol; New England Nuclear) by the random priming method (11) and used to probe a Southern blot of Anabaena sp. strain PCC 7120 chromosomal DNA digested ...

show abstract

Section: Resultsmentioning

confidence: 93%

“…A region of DNA homologous to part of the E. coli gene encoding 3' (rpoC) has been isolated from another cyanobacterium, Nostoc commune UTEX 584 (47). Se-quencing of this region showed that homology to E. coli rpoC is split between two linked genes, rpoCl and rpoC2, in the Nostoc DNA (47).…”

mentioning

confidence: 99%

Evolutionary relationships among eubacteria, cyanobacteria, and chloroplasts: evidence from the rpoC1 gene of Anabaena sp. strain PCC 7120

Bergsland

Haselkorn

1991

J Bacteriol

View full text Add to dashboard Cite

show abstract

“…4, top). 40,41) The core enzyme functions in mRNA polymerization, but requires the sigma () subunit for specific transcription initiation at the promoter. 36,42) General switching in transcription is mainly due to the modulated promoter selectivity of multiple RNAP holoenzymes combined with the replacement of a common core enzyme with several different sigma factors, responding to environmental or internal cellular change.…”

Section: A Light-induced Sigma Factor and Positive Regulationmentioning

confidence: 99%

Regulatory System for Light-Responsive Gene Expression in Photosynthesizing Bacteria:Cis-Elements andTrans-Acting Factors in Transcription and Post-Transcription

Asayama¹

2006

Bioscience, Biotechnology, and Biochemistry

View full text Add to dashboard Cite

Cyanobacteria (blue-green algae) are photosynthesizing organisms that can be used as a model for analyzing light-responsive gene expression. The regulatory system of the light-responsive psbA gene with cis-elements and trans-acting factors was studied at both transcriptional and post-transcriptional levels. Positive regulation comprises DNA curvatures (CIT and RIB), upstream elements (UPE and promoter), and a light-induced sigma factor (SigD) of RNA polymerase in transcription. On the other hand, negative regulation involves mRNA instability through an AU-box under darkness. This two-step process is a candidate for a novel mechanism regulating light-responsive gene expression.

show abstract

“…Preliminary sequencing showed that the two genes are adjacent on the chromosome in the order rpoB rpoC (9), as in other eubacteria that have been investigated (1,17,28) (in the cyanobacteria, rpoC is split into two genes i.e., rpoC1 and rpoC2 [48]). Chater (13) isolated three classes of rifampin-resistant mutants of S. coelicolor, designated rifA, rifB, and rifC.…”

mentioning

confidence: 99%

Mapping of genes involved in macromolecular synthesis on the chromosome of Streptomyces coelicolor A3(2)

et al. 1995

View full text Add to dashboard Cite

The genes for the ␤, ␤, and seven factor subunits of RNA polymerase, for elongation factors EF-Tu1 and EF-Tu3, and for six rRNA operons were mapped on the combined genetic and physical map of the Streptomyces coelicolor chromosome. Like the previously mapped tRNA genes, the RNA polymerase and rRNA genes map to scattered positions. The lack of rRNA operons in the immediate vicinity of the origin of replication (oriC) and the absence of tRNA genes in any of the rRNA operons are novel features of the Streptomyces chromosome.A combined genetic and physical map of the Streptomyces coelicolor A3(2) chromosome, carrying some 150 genes or gene clusters, has been constructed from a combination of the results of linkage analysis via plasmid-mediated conjugation and pulsed-field gel electrophoretic studies of chromosomal fragments generated by rare-cutting restriction enzymes (19,21). Although the linkage analysis included a set of 28 temperaturesensitive lethal mutations (18), none of these was shown to be blocked in specific steps in DNA replication, transcription, or translation. Other such mutations were later implicated in macromolecular synthesis but were not mapped (15). In fact, until recently, the only mapped genes involved in the machinery of nucleic acid or protein synthesis were three putative ribosomal protein or RNA polymerase genes (strA, spcA, and rifA), which were identified by mutations that confer resistance to the antibiotics streptomycin, spectinomycin, and rifampin, respectively. This situation has changed with reports of the mapping of the chromosomal replication origin (11, 50), one putative RNA polymerase factor gene, whiG (14), and 20 tRNA genes (23,35). Here, we report the physical mapping of eight RNA polymerase subunit genes, the two tuf genes for polypeptide chain elongation factors EF-Tu, and the six rRNA operons on the S. coelicolor chromosome. We also discuss current information on the distribution of genes for aspects of macromolecular synthesis in this member of the high-GϩC gram-positive actinomycetes.

show abstract

Cyanobacterial RNA polymerase genes rpoC1 and rpoC2 correspond to rpoC of Escherichia coli

Cited by 57 publications

References 31 publications

Evolutionary relationships among eubacteria, cyanobacteria, and chloroplasts: evidence from the rpoC1 gene of Anabaena sp. strain PCC 7120

Evolutionary relationships among eubacteria, cyanobacteria, and chloroplasts: evidence from the rpoC1 gene of Anabaena sp. strain PCC 7120

Regulatory System for Light-Responsive Gene Expression in Photosynthesizing Bacteria:Cis-Elements andTrans-Acting Factors in Transcription and Post-Transcription

Mapping of genes involved in macromolecular synthesis on the chromosome of Streptomyces coelicolor A3(2)

Contact Info

Product

Resources

About