Complete nucleotide sequence of the Escherichia coli recB gene.

The complete nucleotide sequence of the Escherichia coli recB gene which encodes a subunit of the ATP-dependent DNase, Exonuclease V, has been determined. The proposed coding region for the RecB protein is 3543 nucleotides long and would encode a polypeptide of 1180 amino acids with a calculated molecular weight of 133,973. The start of the recB coding sequence overlaps the 3' end of the upstream ptr gene, and the recB termination codon overlaps the initiation codon of the downstream recD gene, suggesting that these genes may form an operon. No sequences which reasonably fit the consensus for an E. coli promoter could be identified upstream of the proposed recB translational start. The predicted RecB amino acid sequence contains regions of homology with ATPases, DNA binding proteins and DNA repair enzymes.     

Complete nucleotide sequence of the Escherichia coli gdhA gene

The DNA sequence of the gdhA gene of Escherichia coli K12, which encodes the 447 amino acid polypeptide subunit of NADP-specific glutamate dehydrogenase, is presented. The deduced protein sequence is strongly homologous to the corresponding enzyme of the eukaryotic fungus Neurospora crassa. The upstream DNA sequence includes several overlapping promoter consensus sequences. The downstream DNA sequence contains inverted repeats, predicted as forming long stable stem-loop structures in RNA, homologous to those found in several enterobacterial intergenic regions.     

Analysis of the regulatory region of the protease III (ptr) gene of Escherichia coli K-12

The ptr gene of Escherichia coli encodes protease III (Mr 110,000) and a 50-kDa polypeptide, both of which are found in the periplasmic space. The gene is physically located between the recC and recB loci on the E. coli chromosome. The nucleotide sequence of a 1167-bp EcoRV-ClaI fragment of chromosomal DNA containing the promoter region and 885 bp of the ptr coding sequence has been determined. S1 nuclease mapping analysis showed that the major 5' end of the ptr mRNA was localized 127 bp upstream from the ATG start codon. The open reading frame (ORF), preceded by a Shine-Dalgarno sequence, extends to the end of the sequenced DNA. Downstream from the -35 and -10 regions is a sequence that strongly fits the consensus sequence of known nitrogen-regulated promoters. A signal peptide of 23 amino acids residues is present at the N terminus of the derived amino acid sequence. The cleavage site as well as the ORF were confirmed by sequencing the N terminus of mature protease III.     

Extracellular release of protease III (ptr) by Escherichia coli K12

Escherichia coli strains carrying the protease III structural gene (ptr) on a plasmid secreted the protein into the growth medium. Plasmid-encoded beta-lactamase and chloramphenicol acetyl transferase, which served as periplasmic and cytoplasmic markers during cell fractionation, were not released into the growth medium. There appeared to be some strain dependence on the proficiency of the secretion system. Protease III was not detectably processed upon export through the outer cell membrane.     

Complete nucleotide sequence of the glutamate dehydrogenase gene from Escherichia coli K-12

A 2.3-kb PstI-ClaI chromosomal DNA segment, carrying the complete coding region of the glutamate dehydrogenase (GDH) structural gene from Escherichia coli K-12, has been sequenced. The complete amino acid sequence (447 residues) of the GDH monomer has been deduced, and comparisons are made with reported amino acid sequences of GDH from other organisms.     

Cloning, nucleotide sequence, and expression of the Escherichia coli gene encoding carnitine dehydratase.

Carnitine dehydratase from Escherichia coli O44 K74 is an inducible enzyme detectable in cells grown anaerobically in the presence of L-(-)-carnitine or crotonobetaine. The purified enzyme catalyzes the dehydration of L-(-)-carnitine to crotonobetaine (H. Jung, K. Jung, and H.-P. Kleber, Biochim. Biophys. Acta 1003:270-276, 1989). The caiB gene, encoding carnitine dehydratase, was isolated by oligonucleotide screening from a genomic library of E. coli O44 K74. The caiB gene is 1,215 bp long, and it encodes a protein of 405 amino acids with a predicted M(r) of 45,074. The identity of the gene product was first assessed by its comigration in sodium dodecyl sulfate-polyacrylamide gels with the purified enzyme after overexpression in the pT7 system and by its enzymatic activity. Moreover, the N-terminal amino acid sequence of the purified protein was found to be identical to that predicted from the gene sequence. Northern (RNA) analysis showed that caiB is likely to be cotranscribed with at least one other gene. This other gene could be the gene encoding a 47-kDa protein, which was overexpressed upstream of caiB.     

The nucleotide sequence of the gene encoding the K99 subunit of enterotoxigenic Escherichia coli

Abstract The nucleotide sequence of the gene encoding the K99 fimbrial subunit of enterotoxigenic Escherichia coli was determined. It appeared that the subunit is composed of 159 amino acid residues preceded by a N-terminal signal sequence of 22 amino acid residues. The secondary structure of the mature K99 polypeptide and the location of potential antigenic determinants were predicted. A comparison was made between the amino acid sequence of the K99 subunit and the subunits of other fimbrial adhesins.     

The DNA sequence of the gene (rnc) encoding ribonuclease III of Escherichia coli.

The DNA sequence of a 1,076 base pair BglI-BamHI fragment containing the entire rnc gene for ribonuclease III (RNase III) was determined. An open reading frame of 681 base pairs was found in this region which encodes a protein of 227 amino acid residues (calculated molecular weight = 25,218). When this open reading frame was cloned into a high expression vector, pIN-III, a protein of apparent molecular weight of 26,000 was produced upon induction of the cloned gene. This product accounted for up to 5% of the total cellular protein, and comigrated with purified RNase III. RNase III enzyme activity was induced in parallel with the production of the 26,000 molecular weight protein. A putative promoter was found 170 base pairs upstream from the initiation codon. In the long leader region a very stable stem-bulge-stem structure was found which closely resembles typical RNase III cleavage sites. This structure may be cleaved by RNase III to auto-regulate the expression of the rnc gene.     

The nucleotide sequence of the Escherichia coli rts gene

The nucleotide sequence of rts, an essential Escherichia coli gene, has been determined. Transformation of an rts mutant with the plasmid, pJAF1, containing the rts gene resulted in rescue of the defect. The transformation experiments indicate that the rts gene is distinct from the flanking birA, tRNA and tufB genes.