3M8T: Crystal Structure Of The Complex Between Class B3 Beta-Lactamase Bjp-1 And 4-Nitrobenzene-Sulfonamide

Metallo-beta-lactamases (MBLs) are important enzymatic factors in resistance to beta-lactam antibiotics that show important structural and functional heterogeneity. BJP-1 is a subclass B3 MBL determinant produced by Bradyrhizobium japonicum that exhibits interesting properties. BJP-1, like CAU-1 of Caulobacter vibrioides, overall poorly recognizes beta-lactam substrates and shows an unusual substrate profile compared to other MBLs. In order to understand the structural basis of these properties, the crystal structure of BJP-1 was obtained at 1.4-A resolution. This revealed significant differences in the conformation and locations of the active-site loops, determining a rather narrow active site and the presence of a unique N-terminal helix bearing Phe-31, whose side chain binds in the active site and represents an obstacle for beta-lactam substrate binding. In order to probe the potential of sulfonamides (known to inhibit various zinc-dependent enzymes) to bind in the active sites of MBLs, the structure of BJP-1 in complex with 4-nitrobenzenesulfonamide was also obtained (at 1.33-A resolution), thereby revealing the mode of interaction of these molecules in MBLs. Interestingly, sulfonamide binding resulted in the displacement of the side chain of Phe-31 from its hydrophobic binding pocket, where the benzene ring of the molecule is now found. These data further highlight the structural diversity shown by MBLs but also provide interesting insights in the structure-function relationships of these enzymes. More importantly, we provided the first structural observation of MBL interaction with sulfonamides, which might represent an interesting scaffold for the design of MBL inhibitors.
PDB ID: 3M8TDownload
MMDB ID: 87846
PDB Deposition Date: 2010/3/19
Updated in MMDB: 2011/05
Experimental Method:
x-ray diffraction
Resolution: 1.33  Å
Source Organism:

*This structure record is obsolete.

Molecular Components in 3M8T
Label Count Molecule
Proteins (2 molecules)
'blr6230 Protein
Molecule annotation
Chemicals (12 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB