Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0348321 (Haemophilus)
 15,372 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A chromosomal locus, lic3, one of several involved in lipopolysaccharide (LPS) biosynthesis by Haemophilus influenzae, was cloned and its DNA sequence determined. lic3 comprises four closely apposed open reading frames (ORFs). ORF1 includes tandem repeats of the tetramer CAAT and two start codons out of frame with each other are found upstream of the repeats. ORF1 encodes a protein with no known homologues. ORF2 encodes the UDP-galactose-4-epimerase (galE) gene. ORF3 encodes a hydrophobic protein with no known homologues. ORF4 encodes the adenylate kinase (adk) gene. A deletion/insertion mutation lacking the 3' end of ORF1, all of galE, and the 5' end of ORF3 was constructed in the parent Hib strain (RM7004). These mutants had a galE phenotype, as evidenced by galactose sensitivity, altered LPS when grown in the absence of exogenous galactose, and reduced virulence in infant rats.
 ...
PMID:Molecular analysis of a complex locus from Haemophilus influenzae involved in phase-variable lipopolysaccharide biosynthesis. 195 82

The nucleotide sequence of a 4243-bp PstI fragment containing the rec-2 gene of Haemophilus influenzae was determined. The amino acid (aa) sequences of four putative proteins were deduced from the corresponding open reading frames (ORFs). The 2400-bp ORF2 accounted for rec-2, based on the sequences of DNA fragments that contained rec-2::mini-Tn10 mutations. The rec-2 gene encoded a putative 800-aa protein with a M(r) of 90,561. Sequence analysis suggested that the rec-2 product contained nine highly probable integral membrane-spanning segments. Database searches showed that rec-2 was homologous to the comE-ORF3 gene of Bacillus subtilis. This hypothesis is consistent with the known involvement of both of these genes in the passage of transforming DNA through the competent-cell envelope. Although the sequences of the other three ORFs were incomplete, sufficient data were available to allow inferences about their homologies to other genes. ORF4, which overlapped ORF1, was homologous to the Escherichia coli dnaK suppressor gene, dksA, and therefore was named dsh-1 (dnaK suppressor homolog). Mutations in dsh-1 and its putative promoter region caused a mild sensitivity to UV light, but did not affect DNA recombination. ORF3, located downstream from rec-2, was homologous to msbA, an essential gene of E. coli with extensive similarity to the ATP-dependent translocators. ORF3 was named msh-1 (msbA homolog). Mutations in msh-1 had no effects on genetic transformation. The close juxtaposition of rec-2 and msh-1 implied that the expression of msh-1 could be linked to the translation of the rec-2 ORF.
 ...
PMID:Sequence of the rec-2 locus of Haemophilus influenzae: homologies to comE-ORF3 of Bacillus subtilis and msbA of Escherichia coli. 806 12

Neisseria meningitidis FAM20 has recently been shown to produce two Fe-regulated proteins (FrpA and FrpC) related to the RTX family of cytotoxins. Here we report the cloning and DNA sequence of the locus containing the gene encoding the larger meningococcal RTX protein FrpC. FrpC was highly similar to FrpA throughout much of the predicted protein, with two main differences. Whereas the FrpA protein had 13 copies of the nine-amino-acid repeat units typical of RTX proteins, FrpC had 43 copies. The additional copies in FrpC apparently arose from a threefold tandem amplification of a 600bp DNA fragment encoding the repeats. In addition, the frpC gene lacked good promoter consensus sequences. An open reading frame (ORF1) of unknown function was found immediately upstream of frpC, suggesting the possibility that frpC was cotranscribed with ORF1. A probable promoter was found 300bp upstream of ORF1, and it contained a Fur protein-binding sequence found in the promoters of Fe-regulated Escherichia coli genes. DNA upstream of the ORF1/frpC promoter was homologous to IS1016-like elements surrounding capsulation loci of strains of Haemophilus influenzae. A FrpC-like protein (reactive in immunoblots with monoclonal antibody 9D4; multiple reactive bands of about 200 to 120 kDa) was found in five out of eight meningococcal strains but only in one out of 14 other Neisseria, suggesting that FrpC may participate in the pathogenesis of meningococcal disease.
 ...
PMID:Cloning and nucleotide sequence of frpC, a second gene from Neisseria meningitidis encoding a protein similar to RTX cytotoxins. 841 74

A 0.972-kilobase pair DNA fragment from Streptomyces lividans that induces the production of the blue-pigmented antibiotic actinorhodine in S. lividans when cloned on a multicopy plasmid has led to the isolation of a 4-kilobase pair DNA fragment from Streptomyces coelicolor containing homologous sequence. Computer-assisted analysis of the DNA sequence revealed three putative open reading frames (ORFs), ORF1, ORF2, and ORF3. ORF2 extends beyond the sequenced DNA fragment, and its deduced product shares no similarities with any other known proteins in the data bases. ORF3 is also truncated, and its 41-amino acid C-terminal product is identical to the S. coelicolor adenine phosphoribosyltransferase. The 847-amino acid ORF1 protein, with a predicted molecular mass of 94.2 kDa, strongly resembled the relA and spoT gene products from Escherichia coli and the homologs from Vibrio sp. strain S14, Haemophilus influenzae, Streptococcus equisimilis H46A, and Mycoplasma genitalium. Unlike these proteins, the ORF1 amino acid sequence analysis revealed the presence of a putative ATP/GTP-binding domain. A mutant was generated by deleting most of the ORF1 gene that showed an actinorhodine-nonproducing phenotype, while undecylprodigiosin and the calcium-dependent antibiotic were unaffected. The mutant strain grew at a much lower rate than the wild-type strain, and spore formation was delayed. When the gene was propagated on a low copy number vector, not only was actinorhodine production restored, but actinorhodine and undecylprodigiosin production was enhanced in both the mutant and wild-type and morphological differentiation returned to wild-type characteristics. (p)ppGpp synthetase activity was not detected in purified ribosomes from the ORF1-deleted mutant, while it was restored by complementation of this strain.
 ...
PMID:A relA/spoT homologous gene from Streptomyces coelicolor A3(2) controls antibiotic biosynthetic genes. 863 67

A gene essential for the development of genetic competence in Haemophilus influenzae (Hi) was identified as a homolog of the Escherichia coli (Ec) topA gene, which encodes DNA topoisomerase I (TopI). The Hi topA locus was initially identified by mini-Tn10kan mutagenesis. Three independent insertion events within 500 bp of each other resulted in mutant strains that shared a similar phenotype. Each was deficient in competence-induced DNA binding, showed increased sensitivity to UV irradiation, and had an increased doubling time as compared to the wild-type (wt) strain. The nucleotide sequence of a 6.6-kb fragment containing the wt allele was determined. The sequence contained an open reading frame (ORF) of 868 amino acids (aa) that was interrupted by each of the mini-Tn10kan mutations. The deduced aa sequence had a molecular mass of 98 155 Da, a pI of 8.59 and showed strong similarity to Ec TopI. Examination of the topoisomer distribution of a test plasmid in an Hi mutant carrying an insertion in this ORF showed an increase in the level of supercoiling, indicating that TopI is necessary to relax supercoiled DNA in Hi. Complementation studies and insertional inactivation of genes downstream from topA indicated that TopI and not some downstream gene product was essential for competence. Four other ORFs were identified and two of these had homology to known genes. ORF1, which was truncated at one end of the sequenced region, shared strong sequence similarity to the C-terminal end of Ec pyridine nucleotide transhydrogenase beta subunit. ORF4, which was also truncated, showed strong sequence similarity to the N-terminal end of the Ec threonyl-tRNA synthetase.
 ...
PMID:Characterization of the Haemophilus influenzae topA locus: DNA topoisomerase I is required for genetic competence. 863 45

In the human pathogen Staphylococcus aureus, many proteins involved in the infection process are preferentially produced during the stationary growth phase. Using a DNA probe corresponding to the Bacillus subtilis gene encoding the stationary-phase sigma factor SigB (sigmaB), we identified a gene in S. aureus with similarity to B. subtilis sigB. The sigB region was mapped on the SmaI I fragment of the S. aureus chromosome and contains a total of six open reading frames (orf1-6). The deduced amino acid sequences of orf2, orf3, orf4, and orf5 show 64, 67, 71, and 77% similarity to the B. subtilis proteins RsbU, RsbV, RsbW, and SigB, respectively, with SigB representing the sigma factor and the Rsb proteins representing regulators of sigma B. Furthermore, the relative position of the corresponding genes is conserved in B. subtilis, which strongly suggests that we identified the sigB operon of S. aureus, encoding an alternative sigma factor in this organism. The proposed gene products of the two remaining open reading frames show 48-62% similarity to the PemK, ChpAK, and ChpBK growth inhibitors of Escherichia coli (ORF1) and 61% similarity to the ribosomal protein S1 of Haemophilus influenzae (ORF6). Northern blot analysis of the sigB region in S. aureus revealed that four different transcripts are expressed under different conditions of growth phase and stress. These results indicate a complex transcriptional regulation that differs between S. aureus and B. subtilis.
 ...
PMID:The alternative sigma factor sigmaB in Staphylococcus aureus: regulation of the sigB operon in response to growth phase and heat shock 904 55

A 3.9 kb Haemophilus influenzae genomic DNA fragment was cloned in plasmid pUC9 that partially complemented the ultraviolet light sensitivity (UVs) of Escherichia coli uvrC mutant hosts. This fragment also complemented the UVs of H. influenzae uvr-1 (DB112) and uvr-2 (DB116) mutants. It genetically transformed the latter mutants to wild type UV resistance. The nucleotide (nt) sequence of this fragment revealed 3 open reading frames (ORFs). ORF2, now designated uvr-1+ (1746 nt), shows significant similarity in both the nt and amino acid (aa) composition to 7 complete proven or putative uvrC gene sequences. Computer analysis of the DNA sequence revealed several possible regulatory motifs 5' to uvr-1+, including a putative LexA-binding site as an inverted SOS box, located within the 3' region of ORF1, (extensive homology to the E. coli CMP-KDO synthetase gene), upstream of uvr-1+. Further computer analysis has also predicted that the four putative active site amino acids, located in the C-terminal half of each protein, are each situated in an area of secondary structure that are highly conserved.
 ...
PMID:Structure of the Haemophilus influenzae uvr-1+ gene: homology with other uvrC-like genes and characterization of the Haemophilus influenzae uvr-1 and uvr-2 mutations. 927 62

The acylneuraminate lyase gene from Clostridium perfringens A99 was cloned on a 3.3 kb HindIII DNA fragment identified by screening the chromosomal DNA of this species by hybridization with an oligonucleotide probe that had been deduced from the N-terminal amino acid sequence of the purified protein, and another probe directed against a region that is conserved in the acylneuraminate lyase gene of Escherichia coli and in the putative gene of Clostridium tertium. After cloning, three of the recombinant clones expressed lyase activity above the background of the endogenous enzyme of the E. coli host. The sequenced part of the cloned fragment contains the complete acylneuraminate lyase gene (ORF2) of 864 bp that encodes 288 amino acids with a calculated molecular weight of 32.3 kDa. The lyase structural gene follows a noncoding region with an inverted repeat and a ribosome binding site. Upstream from this regulatory region another open reading frame (ORF1) was detected. The 3'-terminus of the lyase structural gene is followed by a further ORF (ORF3). A high homology was found between the amino acid sequences of the sialate lyases from Clostridium perfringens and Haemophilus influenzae (75% identical amino acids) or Trichomonas vaginalis (69% identical amino acids), respectively, whereas the similarity to the gene from E. coli is low (38% identical amino acids). Based on our new sequence data, the 'large' sialidase gene and the lyase gene of C. perfringens are not arranged next to each other on the chromosome of this species.
 ...
PMID:Cloning, sequencing and expression of the acylneuraminate lyase gene from Clostridium perfringens A99. 951 87

The nucleotide sequence of a 3 kb region downstream of pilC1 in Neisseria gonorrhoeae MS11 was analyzed. This region contains two open reading frames, ORF1 and ORF2, and several repetitive DNA elements. ORF1 encodes an outer membrane protein that shows homology to orf98 of Pediococcus acidilactici. PCR with primers specific for ORF1 revealed that the gene is present in all gonococcal strains tested. The other open reading frame, ORF2, is highly homologous to the putative integral membrane protein HI1680 of Haemophilus influenzae.
 ...
PMID:Characterization of the region downstream of the pilus biogenesis gene pilC1 in Neisseria gonorrhoeae. 956 69

The small DNA binding protein Fis is involved in several different biological processes in Escherichia coli. It has been shown to stimulate DNA inversion reactions mediated by the Hin family of recombinases, stimulate integration and excision of phage lambda genome, regulate the transcription of several different genes including those of stable RNA operons, and regulate the initiation of DNA replication at oriC. fis has also been isolated from Salmonella typhimurium, and the genomic sequence of Haemophilus influenzae reveals its presence in this bacteria. This work extends the characterization of fis to other organisms. Very similar fis operon structures were identified in the enteric bacteria Klebsiella pneumoniae, Serratia marcescens, Erwinia carotovora, and Proteus vulgaris but not in several nonenteric bacteria. We found that the deduced amino acid sequences for Fis are 100% identical in K. pneumoniae, S. marcescens, E. coli, and S. typhimurium and 96 to 98% identical when E. carotovora and P. vulgaris Fis are considered. The deduced amino acid sequence for H. influenzae Fis is about 80% identical and 90% similar to Fis in enteric bacteria. However, in spite of these similarities, the E. carotovora, P. vulgaris, and H. influenzae Fis proteins are not functionally identical. An open reading frame (ORF1) preceding fis in E. coli is also found in all these bacteria, and their deduced amino acid sequences are also very similar. The sequence preceding ORF1 in the enteric bacteria showed a very strong similarity to the E. coli fis P region from -53 to +27 and the region around -116 containing an ihf binding site. Both beta-galactosidase assays and primer extension assays showed that these regions function as promoters in vivo and are subject to growth phase-dependent regulation. However, their promoter strengths vary, as do their responses to Fis autoregulation and integration host factor stimulation.
 ...
PMID:Identification and characterization of the fis operon in enteric bacteria. 981 52


1 2 Next >>