Journal of Proteomics & Bioinformatics
Open Access

Abstract

Comparative and Evolutionary Studies of Vertebrate Arylsulfatase B, Arylsulfatase I and Arylsulfatase J Genes and Proteins: Evidence for an ARSB-like Sub-family

Roger S Holmes

Multiple sulfatase genes have been reported on the human genome, including Arylsulfatase B (ARSB), Arylsulfatase I (ARSI) and Arylsulfatase J (ARSJ). ARSB is localized in lysosomes and catalyses the hydrolysis of chondroitin and dermatan sulfate groups. Bioinformatic analyses of vertebrate genomes were undertaken using known human ARSB, ARSI and ARSJ amino acid sequences to study the relatedness and evolution of these genes and proteins. Several domain regions and key residues were conserved including signal peptides, active site residues, metal (Ca2+) and substrate binding sequences, disulfide linkages and N-glycosylation sites. The genes were widely expressed in human tissues with highest levels in esophagus (ARSB), lung (ARSI) and fibroblast cells (ARSB). Human ARSB was larger in size (>200 kb) and contained 8 coding exons, whereas ARSI and ARSJ contained only 2 coding exons among all vertebrate genomes examined. CpG islands were located within the 5’ region of the human ARSB, ARSI and ARSJ genes. In addition, six and seven miR-binding sites were observed within the 3’-UTR of human ARSB and ARSJ genes, respectively. Phylogenetic analyses describe a proposal for a primordial invertebrate SUL-3 gene serving as an ancestor for unequal cross over events generating these three genes in vertebrate genomes.