Molecular cloning and analysis of a cDNA coding for nucleoside diphosphatekinase from ryegrass

A full-length cDNA, LpNDPK, encoding ryegrass nucleoside diphosphate kinase (EC 2.7.4.6) has been cloned acid sequenced. The nucleotide sequence of th e clone contains an open reading frame of 450 nucleotides encoding a protei n of 150 amino acid residues with a calculated molecular mass of 16.5 kDa a nd a P-i of 6.62, The LpNDPK encoded protein possesses substantial homology with nucleoside diphosphate kinases (NDPKs) isolated and cloned form other sources: the highest identity (86%) was observed with NDPK from sugarcane (Saccharum officinarum). Amino acid comparisons with other NDPKs show that the presented ryegrass NDPK sequence also contains several motifs and speci fic residues crucial for catalytic activity which are highly conserved amon g other NDPKs. RT-PCR expression analysis using primers covering the coding region of LpNDPK revealed that the ryegrass NDPK gene is equally expressed in stem. leaf, and flower tissue.