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)

Very little is known about specific mechanisms for zinc accumulation and transport in bacteria. In this study a putative adhesin B in Hemophilus influenzae, the product of gene HI0119, has been identified as a periplasmic zinc-binding protein (PZP1). A pzp1-deficient mutant has been constructed which is defective for growth under aerobic conditions and grows poorly under anaerobic conditions. The growth defect is specifically rescued by supplementing the growth medium with high concentrations of zinc. Subcellular fractionation was used to localize PZP1 to the periplasmic region in a nontypeable H. influenzae strain and in a transfected recombinant Escherichia coli strain (TApzp1). Recombinant PZP1, purified from a periplasmic extract of E. coli strain TApzp1, contained approximately two zinc atoms/protein molecule as determined by neutron activation analysis and atomic absorption spectroscopy. The zinc atoms could be removed by incubation with EDTA, and, by further addition of zinc, a total of five zinc atoms/PZP1 could be bound. Direct binding of 65Zn to the recombinant protein by Western blot was demonstrated. Taken together, these results provide direct evidence that PZP1 plays a key role in zinc uptake by H. influenzae.
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PMID:Identification of the key protein for zinc uptake in Hemophilus influenzae. 936 Sep 76

A search of the gonococcal genome database using the known zinc-binding protein (znuA) sequences from Escherichia coli and Haemophilus influenzae identified an open reading frame encoding a putative gonococcal ZnuA. The consensus amino acid sequence of this open reading frame possessed a characteristic 30-amino acid histidine-rich metal-binding motif (repetitive HDH sequence) containing 43% histidine and 37% aspartic acid and glutamic acid. Subsequently, two adjacent open reading frames with homology to E. coli and H. influenzae znuB and znuC were located upstream of znuA. When partially purified from sonicated cell-free supernatants by CM-Sepharose chromatography, the mature gonococcal ZnuA had an estimated molecular mass of 38 kDa by SDS-PAGE. The presence of a DNA sequence encoding a 19-amino acid signal peptide and the solubility of the mature ZnuA suggested that this protein was located in the periplasm. Inactivation of the Neisseria gonorrhoeae F62 znuA by insertional mutagenesis resulted in a mutant that had a growth rate lower than that of the wild-type parent strain and that required high concentrations of ZnCl2 (> or = 200 microM) for optimal growth. Using a chemically defined agar medium, the gonococcal ZnuA mutant grew only in the presence of Zn(2+), whereas Mg(2+), Ca(2+), Ni(2+), Fe(2+), Cu(2+), Mn(2+) and Cd(2+) had either no effect or were growth inhibitory.
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PMID:Identification and characterization of a high-affinity zinc uptake system in Neisseria gonorrhoeae. 1150 9