Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1832526 (PCC)
 5,967 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Transposon-generated mutant N10 of Anabaena sp. strain PCC 7120 has a Het- phenotype (A. Ernst, T. Black, Y. Cai, J.-M. Panoff, D. N. Tiwari, and C. P. Wolk, J. Bacteriol. 174:6025-6032, 1992). Reconstruction of the transposon mutation reproduced a Het- phenotype, but reconstructions with other insertions at the position of the transposon produced strains that form multiple contiguous heterocysts. Sequence analysis around the site of insertion of the transposon showed that the insertion lies within the 5' end of an 861-bp open reading frame (ORF) (hetN). The product of translation of hetN (HetN) shows extensive similarity to NAD(P)H-dependent oxidoreductases that are involved in biosyntheses of fatty acids, poly-beta-hydroxybutyrate, nod factor, and polyketides. A second, 1,518-bp ORF (hetM) that ends 556 bp 5' from the start of hetN appears to encode a protein that has at least two functional domains: its amino terminus is similar to an acyl carrier protein, while its central portion is similar to domains of proteins that perform reductive reactions. A third, 711-bp ORF (hetI) encoded on the opposite strand ends 42 bp away from the 3' end of hetN. The protein encoded by hetI, HetI, is similar to Sfp from Bacillus subtilis and EntD from Escherichia coli, proteins that are required for the biosynthesis or export of cyclic peptides. Clones from a lambda-EMBL3 library that contain the wild-type DNA for hetN do not complement the hetN::Tn5-1063 mutation in N10. The presence of hetN, as the only ORF, on a replicating plasmid suppresses heterocyst formation in wild-type cells, whereas the additional presence of hetI alleviates this effect.
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PMID:Analysis of a Het- mutation in Anabaena sp. strain PCC 7120 implicates a secondary metabolite in the regulation of heterocyst spacing. 815 96

NADPH-dependent oxidoreductases are useful catalysts for the production of chiral synthons. However, preparative applications of oxidoreductases require efficient methods for in situ regeneration of the expensive nicotinamide cofactors. An advantageous method for cofactor regeneration is the construction of bifunctional fusion proteins composed of two enzymes, one catalysing the reduction reaction and the other one mediating the recycling of cofactors. Herein, we describe the in-frame fusion between an NADP+-accepting mutant of FDH (formate dehydrogenase) from Mycobacterium vaccae N10 and KR [3-ketoacyl-(acyl-carrier-protein) reductase] from Synechococcus sp. strain PCC 7942. The generation of linker insertion mutants led to a fusion protein exhibiting 100 and 80% of the enzymatic activities of native KR and FDH respectively. Escherichia coli cells expressing the fusion protein showed an approx. 2-fold higher initial reaction rate in the production of chiral alcohols than cells expressing the enzymes separately. The application of the engineered fusion protein in whole-cell bioreduction of pentafluoroacetophenone resulted in a substrate conversion of 99.97% with an excellent enantiomeric excess of 99.9% (S)-1-(pentafluorophenyl)ethanol.
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PMID:Enantioselective reduction of prochiral ketones by engineered bifunctional fusion proteins. 2059 May 27