CLONING AND CHARACTERIZATION OF A GENE RESPONSIBLE FOR THE LATHYRUS-SATIVUS NEUROTOXIN DEGRADATION

A plasmid pBYA1, capable of degrading the Lathyrus sativus neurotoxin beta-N-oxalyl amino alanine (BOAA), was isolated from a soil microbe a nd a physical map of the plasmid constructed. A partial Sau3A library of the plasmid was then prepared in pUC18 and a recombinant clone with a 1.8 kb insert capable of growing In Mg medium, with BOAA as sole so urce of carbon and nitrogen, was isolated. A nested set of deletions o f this 1.8 kb fragment was then generated using Bal31 and the shortene d fragments subcloned in the vector pUC18. Each of these clones were s equenced by Sanger's dideoxy method and the sequences overlapped and a nalysed. The 1.8 kb BOAA degrading fragment was found to contain a 630 nucleotide long coding stretch, coding for 191 amino acids. The initi al 56 nucleotides were found to contain sequences resembling the Pribn ow-Schaller box of prokaryotes, the ''-35'' sequences and a sequence r esembling the ''-43'' region of the lac promoter.