Recombinant DNA sequences encoding phospholipase

Reference Number: K 94-28

Inventors: Wang, Xuemin

USPTO Link: 5670366

Invention Summary

The present invention overcomes the problems outlined above and provides substantially isolated and purified eukaryotic complementary DNA sequences (i.e., cDNAs) which encode for plant phospholipases such as phospholipase D, and particularly phosphatidylcholine-hydrolyzing phospholipase D. Such DNA sequences preferably consist essentially of DNA sequences encoding for plant phospholipases. A particular sequence encoding for PLD is derived from castor bean (Ricinus communis) and comprises a 2424-bp open reading frame sequence between nucleotides 171 and 2595 of SEQ ID #1. However, the invention also embraces sequence having sufficient similarity to the aforementioned open reading frame to code for related plant phospholipases. Generally speaking, such sufficient similarity should comprise at least about 50% identity of nucleotides (homology), and more preferably about 70% identity.

The invention also provides expression vectors including therein genetic inserts having nucleotide sequences coding for plant phospholipases in host organisms. Preferably, such vectors comprise a plasmid which can be introduced into a host organism such as E. coli. Such transformed cells including a recombinant DNA molecule such as a plasmid are also within the ambit of the invention.

Additionally, the invention provides recombinantly-derived plant phospholipases such as phospholipase D. An exemplary phospholipase D is made up of 808 amino acids as specified in SEQ ID #2. Those skilled in the art will understand, however, that the invention also includes similar or analogous plant phospholipases, particularly those having greater than 50% (preferably greater than 70%) amino acid residue identity as compared with SEQ ID #2. Such phospholipases could include those of classes a1, a2, b and c which could have functionalities in various aspects of metabolism including fatty acid biosynthesis.