Chicken poly(ADP-ribose) synthetase: complete deduced amino acid sequence and comparison with mammalian enzyme sequences

Abstract The complete nucleotide (nt) sequence of the cDNA encoding the chicken poly(ADP-ribose) synthetase has been determined. Positive clones overlapping the 5′ region or the 3′ region of the cDNA have been isolated from a λgt10 hen oviduct cDNA library using two human cDNA probes. The missing middle portion has been obtained by the polymerase chain reaction procedure. A single 3033-nt open reading frame from start codon to stop codon encodes a sequence of 1011 amino acid residues. The alignment of this sequence with those from human and mouse reveals overall identities of 79% and 77%, respectively. However, an identity of about 82% is obtained in the DNA-binding domain within the two zinc fingers, and an even higher similarity (85–87%) is observed in the NAD-binding domain. The isolated clones consistently hybridize on chicken Northern blots to an mRNA species of about 4 kb, whereas they do not cross-hybridize with RNA blots of Drosophila melanogaster . Thus, it appears that, even if the functional properties of the enzyme are maintained, the cDNA identity will be much decreased in nonvertebrate organisms.