Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.5.1.4 (deaminase)
 5,113 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have analysed a gene cluster in the 67 center dot 4-76 center dot 0 min region of the Escherichia coli chromosome, revealed by recent systematic genome sequencing. The genes within this cluster include: (1) five genes encoding homologues of the E. coli mannose permease of the phosphotransferase system (IIB, IIB', IIC, IIC' and IID); (2) genes encoding a putative N-acetylgalactosamine 6-phosphate metabolic pathway including (a) a deacetylase, (b) an isomerizing deaminase, (c) a putative carbohydrate kinase, and (d) an aldolase; and (3) a transcriptional regulatory protein homologous to members of the DeoR family. Evidence is presented suggesting that the aldolase-encoding gene within this cluster is the previously designated kba gene that encodes tagatose-1,6-bisphosphate aldolase. These proteins and a novel IIAMan-like protein encoded in the 2 center dot 4-4 center dot 1 min region are characterized with respect to their sequence similarities and phylogenetic relationships with other homologous proteins. A pathway for the metabolism of N-acetylgalactosamine biochemically similar to that for the metabolism of N-acetylglucosamine is proposed.
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PMID:Novel phosphotransferase genes revealed by bacterial genome sequencing: a gene cluster encoding a putative N-acetylgalactosamine metabolic pathway in Escherichia coli. 893 97

Functional and structural properties of several truncated or mutated variants of Candida albicans Gfa1p (glucosamine-6-phosphate synthase) were compared with those of the wild-type enzyme. Fragments encompassing residues 1-345 and 346-712 of Gfa1p, expressed heterogeneously in bacterial host as His6 fusions, were identified as the functional GAH (glutamine amidehydrolysing) and ISOM (hexose phosphate-isomerizing) domains respectively. It was found that the native GAH domain is monomeric, whereas the native ISOM domain forms tetramers, as does the whole enzyme. Spectrofluorimetric and kinetic studies of the isolated domains, the Delta218-283Gfa1p mutein and the wild-type enzyme revealed that the binding site for the feedback inhibitor, uridine 5'-diphospho-N-acetyl-D-glucosamine, is located in the ISOM domain. Inhibitor binding affects amidohydrolysing activity of the GAH domain and, as a consequence, the GlcN-6-P (D-glucosamine-6-phosphate)-synthetic activity of the whole enzyme. The fragment containing residues 218-283 is neither involved in ligand binding nor in protein oligomerization. Comparison of the catalytic activities of Gfa1p(V711F), Delta709-712Gfa1p, Gfa1p(W97F) and Gfa1p(W97G) with those of the native Gfa1p and the isolated domains provided evidence for an intramolecular channel connecting the GAH and ISOM domains of Gfa1p. The channel becomes leaky upon deletion of amino acids 709-712 and in the W97F and W97G mutants. The Trp97 residue was found to function as a molecular gate, opening and closing the channel. The W97G and V711F mutations resulted in an almost complete elimination of the GlcN-6-P-synthetic activity, with the retention of the amidohydrolase and sugar phosphate-isomerizing activities.
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PMID:Functional domains and interdomain communication in Candida albicans glucosamine-6-phosphate synthase. 1730 46