Abstract: Strian TP-3 was induced by transposon mini-Tn5 on suicide plasmid pUT, and a mutant strain which could not produce sphingan Ss was screened. The spsK gene of TP-3 was obtained by the method of Tn5 flanking PCR and LP-RAPD. The spsK gene coding region includes 801 bp and encodes glycosyl transferase. The bioinformatics analysis reveals that spsK from strain TP-3 showed the highest of 47% amino acid sequence identity with glycosyl transferase from biosynthesis of diutan and S88 sphingan. SpsK protein from strain TP-3 belongs to the glycosyl transferase GT-A family with the typical motif of G-loop and DXD.

Key words: Sphingomonas sp., sphingan Ss, glycosyl transferase, bioinformatics