Process for the isolation and characterization of a gene enzyme system for inactivation of the herbicide phenmedipham and transfer of the gene into plants to produce herbicide-tolerant plants

A purified carbamate hydrolase isolatable from Arthrobacter oxidans having a molecular weight in the range of approximately 50-60 kd, an isoelectric point of approximately pI=6.2, and a pH optimum of approximately 6.8.

A DNA fragment encoding an amino acid sequence selected from the group consisting of SEQ ID NO:1 and SEQ ID NO:2.

An oligonucleotide consisting essentially of a sequence selected from the group consisting of:

• ##STR6##

A method of isolating a carbamate hydrolase gene from Arthrobacter oxidans comprising the steps of:

• probing a gene library with a nucleotide fragment selected from the group consisting of SEQ ID NO:3, SEQ ID NO:4 and SEQ ID NO:5, and fragments thereof, under conditions that allow specific hybridization to a carbamate hydrolase gene:
• and isolating a hybridizing carbamate hydrolase gene.

A method of isolating a carbamate hydrolase gene from Arthrobacter oxidans comprising the steps of:

• probing a gene library with a nucleotide fragment encoding an amino acid sequence selected from the group consisting of SEQ ID NO:
• 1,SEQ ID NO:2, and fragments thereof, under conditions that allow specific hybridization to a carbamate hydrolase gene;
• and isolating a hybridizing carbamate hydrolase gene.