USE OF TN5TAC1 TO CLONE A PEL GENE ENCODING A HIGHLY ALKALINE, ASPARAGINE-RICH PECTATE LYASE ISOZYME FROM AN ERWINIA-CHRYSANTHEMI EC16 MUTANT WITH DELETIONS AFFECTING THE MAJOR PECTATE LYASE ISOZYMES

Erwinia chrysanthemi mutant CUCPB5047, Delta(pelA pelE) Delta(pelB pelC)::28bp Delta(pelX) Delta 4bp pehX::Omega Cm-r, was constructed, mutated with Tn5tac1, and screened for isopropyl-beta-D-thiogalactopyranoside dependent pectate lyase (Pel) production. A Km(r) SacI fragment from the hyperexpressing Pel(+) mutant CUCPB5066 was cloned into Escherichia coli and sequenced. The gene identified, pelL, encodes a novel, asparagine-rich, highly alkaline enzyme that is similar in primary structure to PelX and in enzymological properties to PelE.