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A Comparative Analysis of the Sugar Phosphate Cyclase Superfamily Involved in Primary and Secondary Metabolism
Author(s) -
Wu Xiumei,
Flatt Patricia M.,
Schlörke Oliver,
Zeeck Axel,
Dairi Tohru,
Mahmud Taifo
Publication year - 2007
Publication title -
chembiochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.05
H-Index - 126
eISSN - 1439-7633
pISSN - 1439-4227
DOI - 10.1002/cbic.200600446
Subject(s) - aminocyclitol , biochemistry , sugar phosphates , biosynthesis , heterologous expression , biology , gene cluster , secondary metabolism , gene , actinomycetales , cyclase , streptomyces hygroscopicus , chemistry , enzyme , aminoglycoside , bacteria , streptomyces , recombinant dna , antibiotics , genetics
Sugar phosphate cyclases (SPCs) catalyze the cyclization of sugar phosphates to produce a variety of cyclitol intermediates that serve as the building blocks of many primary metabolites, for example, aromatic amino acids, and clinically relevant secondary metabolites, for example, aminocyclitol/aminoglycoside and ansamycin antibiotics. Feeding experiments with isotopically labeled cyclitols revealed that cetoniacytone A, a unique C 7 N‐aminocyclitol antibiotic isolated from an insect endophytic Actinomyces sp., is derived from 2‐ epi ‐5‐ epi ‐valiolone, a product of SPC. By using heterologous probes from the 2‐ epi ‐5‐ epi ‐valiolone synthase class of SPCs, an SPC homologue gene, cetA , was isolated from the cetoniacytone producer. cetA is closely related to BE‐orf9 found in the BE‐40644 biosynthetic gene cluster from Actinoplanes sp. strain A40644. Recombinant expression of cetA and BE‐orf9 and biochemical characterization of the gene products confirmed their function as 2‐ epi ‐5‐ epi ‐valiolone synthases. Further phylogenetic analysis of SPC sequences revealed a new clade of SPCs that might regulate the biosynthesis of a novel set of secondary metabolites.