CLONING AND SEQUENCE-ANALYSIS OF THE CDNA FOR ARGININE KINASE OF LOBSTER MUSCLE

Arginine kinase belongs to an evolutionary conserved family of ATP:gua nidino phosphotransferases, whose members play an important role in en ergy metabolism. In this work, a lambdagt11 lobster muscle library was constructed and screened by using both polyclonal antibodies and two synthetic oligonucleotides. The complete amino acid sequence of argini ne kinase (ATP:L-arginine N-phosphotransferase, EC 2.7.3.3) from lobst er muscle was determined by cloning and sequencing the DNA complementa ry to its mRNA. The identity of the clone was confirmed by comparing t he amino acid sequence deduced by nucleotide sequence analysis with pr eviously published partial sequences of amino- and carboxyl-terminal r egions of the enzyme and some of its fragments (Regnouf, F., Kassab, R ., Debuire, B., Richard, C., and Han K. K. (1981) Int. J. Peptide Prot ein Res. 17, 143-155). The nucleotide sequence of the cDNA was found t o contain an open reading frame encoding 355 amino acid residues with a calculated molecular mass of 39,830 daltons. This enzyme exhibits a significant sequence identity to those of representative members of th e guanidino kinase family, including creatine kinase. This report repr esents the first molecular cloning and sequencing of an ATP-guanidino phosphotransferase which is not a creatine kinase isoform.