title: T4 polynucleotide kinase; cloning of the gene (pseT) and amplification of its product.
abstract: The T4 gene (pseT) for polynucleotide kinase (pnk) has been cloned in lambda. Induction of a lambda E-W-S-cI857 prophage in which the pseT gene can be transcribed from the late lambda promoter, PR1, leads to greater than 100-fold amplification of pnk activity; pnk comprises approximately 7% of the total soluble cell protein. The purified enzyme, as expected, is both a 5'-kinase and a 3'-phosphatase. The amino acid sequence deduced from an open reading frame identified as the pseT gene contains a sequence which corresponds particularly well with that part of the adenine nucleotide binding site of adenylate kinase shown to form a flexible loop. A deletion mutant that lacks 5'-kinase activity, and possibly also 3'-phosphatase activity, has lost two amino acids from within the proposed loop structure. A second region of the pnk sequence shares homology with phosphoglycerate kinase, yeast inorganic pyrophosphatase and histone 2b from various organisms.
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D005784:Gene Amplification; D005786:Gene Expression Regulation; D005796:Genes; D005814:Genes, Viral; D008970:Molecular Weight; D010770:Phosphotransferases / Q000235:genetics*; D011116:Polynucleotide 5'-Hydroxyl-Kinase / Q000235:genetics*; D013604:T-Phages / Q000235:genetics*; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000235:genetics; D014779:Virus Replication
chemical_list: D014764:Viral Proteins; D010770:Phosphotransferases; D011116:Polynucleotide 5'-Hydroxyl-Kinase