CRYSTAL STRUCTURE OF PEPTIDASE M28 PRECURSOR (YP_926796.1) FROM SHEWANELLA AMAZONENSIS SB2B AT 1.70 A RESOLUTION 3IIB HYDROLASE, YP_926796.1, PEPTIDASE M28 PRECURSOR, STRUCTURAL GENOMICS, JOINT CENTER FOR STRUCTURAL GENOMICS, JCSG, PROTEIN STRUCTURE INITIATIVE, PSI-2, PEPTIDASE FAMILY M28