“…Eight X-ray structures of apo-enzymes, TEM-1 and TOHO-1 from Escherichia coli (16,17), PC1 from Staphylococcus aureus (18), SHV from Klebsiella pneumoniae (19), NMC-A from Enterobacter cloacae (20), MFO from Mycobacterium fortuitum (PDB entry: 1MFO), BLIC from Bacillus licheniformis (21), and SAG from Streptomyces albus G (22) have been solved. These enzymes display a very similar fold and the detailed comparisons of the structures were helpful in relating some by guest on May 9, 2018 http://www.jbc.org/ Downloaded from 5 significant differences in substrate profile to local structural features (23,24).…”