The gene of chlamysin, a marine invertebrate-type lysozyme, is organized similar to vertebrate but different from invertebrate chicken-type lysozyme genes.
In a recent publication we reported the protein purification, characterization, and the gene isolation of a cDNA encoding the antibacterial cold-active lysozyme-like protein chlamysin from the marine bivalve Chlamys islandica. A 4.2 kb genomic chlamysin gene has now been amplified and sequence-analyzed. By comparison to the cDNA sequence and its translation product, the coding region was found separated in four exons of 38-252 bp. The introns range in size from 0.8 to 1.5 kb, and have traditional spliceosomal intron 5'-GT donor and 3'-AG acceptor sites for splicing. Two of the introns contain multiple copies of three sequence motifs not found repeated in other published genes. The over-all gene organization of chlamysin resembles chicken-type (c-type) lysozyme genes in vertebrates, but is different from the three-exon structure in invertebrate c-type lysozyme genes. A phylogenetic analysis of invertebrate-type (i-type) and c-type lysozyme proteins demonstrated a large evolutionary distance between the i-type and the c-type enzyme classes. Exons of the i-type genes are not equally organized according to their homolog protein domains.
Nilsen
I W
IW
Center of Marine Biotechnology, Norwegian Institute of Fisheries and Aquacultures Ltd., N-9291, Tromsø, Norway. ingewn@fiskforsk.norut.no
Myrnes
B
B
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D049872:Bivalvia / Q000201:enzymology* / Q000235:genetics; D002645:Chickens; D018076:DNA, Complementary; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D009113:Muramidase / Q000145:classification / Q000235:genetics*; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D020080:Tandem Repeat Sequences; D014714:Vertebrates
D018076:DNA, Complementary; C403411:chlamysin; D009113:Muramidase