Cloning, expression, and characterization of the Escherichia coli K-12 rfaD gene.

摘要: Abstract The rfaD gene encodes ADP-L-glycero-D-mannoheptose-6-epimerase, an enzyme required for the biosynthesis of lipopolysaccharide precursor ADP-L-glycerol-D-mannoheptose. The precise localization on a 1.3-kilobase SspI-HpaI fragment is reported. and flanking regions were completely sequenced. location physical map Escherichia coli chromosome was determined. Primer extension studies used to define regulatory region gene. cloned directed synthesis 37,000-dalton polypeptide in several vivo vitro expression systems. N-terminal analysis purified ADP-L-glycero-D-mannoheptose-6-epimerase confirmed first 34-amino-acid sequence deduced from nucleotide coding region. primary structure protein contains fingerprint ADP-binding beta alpha fold at N terminus.