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

Several chromosomal loci are involved in lipopolysaccharide (LPS) biosynthesis by Haemophilus influenzae. Two of these, lic1 and lic2, contain multiple open-reading frames (ORFs) and include tandem repeats of the tetramer CAAT within and at the 5' end of the coding region of the first ORF in each locus. Variation in the number of repeats of CAAT is involved in the variable expression of LPS epitopes, and genes within these loci are involved in the biosynthesis of these epitopes. lic3 also contains multiple ORFs and the CAAT repeats in the same arrangement as in the other two lic loci. However, in lic3 metabolic functions are encoded by the downstream genes. ORF2 is galE, encoding uridine 5'-diphosphogalactose 4-epimerase, and ORF4 is adk, encoding adenylate kinase. A mutant H. influenzae with a deleted galE gene had an altered LPS when grown on media lacking galactose and was of reduced virulence in infant rats.
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PMID:Molecular biology of phase-variable lipopolysaccharide biosynthesis by Haemophilus influenzae. 158 88

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.
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PMID:Molecular analysis of a complex locus from Haemophilus influenzae involved in phase-variable lipopolysaccharide biosynthesis. 195 82

Multilocus enzyme electrophoresis was adapted to the study of Haemophilus influenzae. Protein extracts from sonicated whole bacteria were subjected to starch gel electrophoresis. After staining with substrates, the position of each isoenzyme (electromorph) was registered. Each isolate was assigned an electrophoretic type (ET) by the combination of electromorphs for the enzymes stained. Twenty-seven enzymes were tested; 12 were expressed in H. influenzae. Six enzymes were selected for subsequent study: malate dehydrogenase (MDH), phenylalanylleucine peptidase (PE2), 6-phosphogluconate dehydrogenase (6PG), adenylate kinase (AK), glucose 6-phosphate dehydrogenase (G6P), and phosphoglucose isomerase (PGI). They were polymorphic and occurred in all isolates. Six electromorphs were found for PE2, G6P, and PGI, five for MDH, four for 6PG, and three for AK. PE2, G6P, and PGI contributed most of the ET resolution (48 of 49 ETs). Multilocus enzyme electrophoresis showed several advantages over previous typing techniques. An ET could be assigned to both typable and nontypable (NT) isolates. The technique was powerful in resolving differences among isolates. The 94 isolates comprised 49 ETs, five biotypes, and six capsular types and NT isolates. Strains known to be related expressed the same ET, e.g., RAB b+ and b-, ET12; Ma a+ and a-, ET1. ET variability among type b isolates was low; 26 of 28 clinical isolates expressed ET14; 2 of 28 expressed ET13 and ET15, differing from ET14 by one electromorph each. In contrast, the 47 NT isolates comprised 38 different ETs. No ETs were shared between non-type b capsulated strains and type b or NT strains. Interestingly, five NT isolates expressed the same ET as type b strains. (iv) Strains of the same capsular type but different biotypes expressed different ETs. ET determinations will thus be useful in studying the epidemiology and evolution of H. influenzae.
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PMID:Application of multilocus enzyme gel electrophoresis to Haemophilus influenzae. 352 33

The adk gene from the Gram-negative pathogen Bordetella pertussis was cloned by complementing the thermosensitive Escherichia coli adk strain CR341T28. B. pertussis adenylate kinase is a 218-amino-acid protein that has high similarity with adenylate kinase from Escherichia coli and Hemophilus influenzae (57%). A distinct characteristic of enzyme from B. pertussis, not found in other bacterial adenylate kinases, is the presence of a tryptophan residue at position 185. Although distant from the catalytic site, this single tryptophan serves as a convenient probe for monitoring the binding of nucleotide substrates or analogs to the enzyme. Differential scanning calorimetry and equilibrium unfolding experiments in guanidine.HCl indicate similar stabilities for adenylate kinase from B. pertussis and E. coli. An extensive comparison between physico-chemical properties of adenylate kinase from B. pertussis and the enzyme from E. coli showed that the kinetic and structural properties of the two enzymes are very similar. However, infrared spectroscopy has allowed to identify small but significant differences in the secondary structure of the two proteins.
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PMID:Structural and physico-chemical characteristics of Bordetella pertussis adenylate kinase, a tryptophan-containing enzyme. 828 44