Luciferases, aryl- and fatty-acyl CoA synthetases, and non-ribosomal peptide synthetase proteins belong to the class I adenylate-forming enzyme superfamily. The reaction catalyzed by the adenylate-forming enzymes is categorized by a two-step process of adenylation and thioesterification. Although all of these proteins perform a similar two-step process, each family may perform the process to yield completely different results.
View Article and Find Full Text PDFUnlabelled: Heme oxygenases (HO) catalyze the breakdown of heme, aiding the recycling of its components. Several other enzymes have homologous tertiary structures to HOs, while sharing little sequence homology. These homologues include thiaminases, the hydroxylase component of methane monooxygenases, and the R2 component of Class I ribonucleotide reductases (RNR).
View Article and Find Full Text PDFUnlabelled: UDP-glucose dehydrogenase (UDPGDH), UDP-N-acetyl-mannosamine dehydrogenase (UDPNAMDH) and GDP-mannose dehydrogenase (GDPMDH) belong to a family of NAD (+)-linked 4-electron-transfering oxidoreductases called nucleotide diphosphate sugar dehydrogenases (NDP-SDHs). UDPGDH is an enzyme responsible for converting UDP-d-glucose to UDP-d-glucuronic acid, a product that has different roles depending on the organism in which it is found. UDPNAMDH and GDPMDH convert UDP-N-acetyl-mannosamine to UDP-N-acetyl-mannosaminuronic acid and GDP-mannose to GDP-mannuronic acid, respectively, by a similar mechanism to UDPGDH.
View Article and Find Full Text PDFAn algorithm for detecting amino acid residues characteristic of individual protein families from within aligned collections of paralogous sequences, and its application to the ALDH3 family versus the rest of the ALDH extended family is described. Residues illuminated by this analysis include a key intramolecular tether, a lysine that makes an intersubunit contact at the dimer interface, three residues in close association with the substrate-binding funnel, and a pair of residues suggested to participate in proton relay during the catalytic cycle.
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