... the substrate-binding site in the hydrophobic environment, and alsosuggest that Cys341 may be involved in the catalysis in amanner other than substrate binding. However, the precisetype of ... at the S1binding site [5–7,9], but the hydrophobicity of the thiolgroup also plays a role in substrate binding andinteracting with the hydrophobic residues of the S1subsite. However, the ... chain is in effect. In fact, our results for C341V andC341F provide support for a scenario in which the hydrophobicity of the SH group of Cys341 is importantfor substrate binding and maintaining...