3bsqA Introduction

Sulfatases are enzymes that hydrolyze sulfate ester bonds of substrates. These are categorized as EC 3.1.6. in enzyme classifications. They all participate in metabolic processes, most of the family members are shown to contain a highly conserved cystine residue and a bivalent metal binding site. Majority of sulfatases are located in lysosomes with an acidic pH optima; however human stroid sulfatase is found in endoplasmic reticulums (ER) with a neutral pH potima. most of the sulfatases are water soluble including Arylsulfatase A (ASA), Arylsulfatase B (ASB) and N-acetylgalactosamine-6-sulfatase (G6S) are water soluble. The sulfatase in our focus is arylsulfatase K (ASK), were the crystal structure is been solves, but no functional characterisation is done to the date. In this experiment we looked at proteins with sequence conservation, structural similarity, other proteins that ASK is known to interact with, and the level of conservation of some key residues that may be involved in its catalytic activity; to determine the possible function of the protein [[1]] .

Function of some other sulfatases were found through a literature search. ASA is a lysosomal enzyme which hydrolyzes cerebroside sulphate. ASB is also a lysosomal enzyme which hydrolyzes the sulphate ester group from N-acetylgalactosamine 4-sulphate group of dermatine sulphate. The range of substrates catalysed by sulfatases is diverse, including cerebroside sulfate, dermatan sulfate, heparan sulfate, heparin and keratan sulfate, and steroid sulfates [[2]]