3HJT: Structure Of Laminin Binding Protein (lmb) Of Streptococcus Agalactiae A Bifunctional Protein With Adhesin And Metal Transporting Activity

Citation:
Abstract
Adhesion/invasion of pathogenic bacteria is a critical step in infection and is mediated by surface-exposed proteins termed adhesins. The crystal structure of recombinant Lmb, a laminin-binding adhesin from Streptococcus agalactiae, has been determined at 2.5 A resolution. Based on sequence and structural homology, Lmb was placed into the cluster 9 family of the ABC (ATP-binding cassette) transport system. The structural organization of Lmb closely resembles that of ABC-type solute-binding proteins (SBPs), in which two structurally related globular domains interact with each other to form a metal-binding cavity at the interface. The bound zinc in Lmb is tetrahedrally coordinated by three histidines and a glutamate from both domains. A comparison of Lmb with other metal transporters revealed an interesting feature of the dimerization of molecules in the crystallographic asymmetric unit in all zinc-binding transporters. A closer comparison of Lmb with the zinc-binding ZnuA from Escherichia coli and Synechocystis 6803 suggested that Lmb might undergo a unique structural rearrangement upon metal binding and release. The crystal structure of Lmb provides an impetus for further investigations into the molecular basis of laminin binding by human pathogens. Being ubiquitous in all serotypes of group B streptococcus (GBS), the structure of Lmb may direct the development of an efficient vaccine.
PDB ID: 3HJTDownload
MMDB ID: 78427
PDB Deposition Date: 2009/5/22
Updated in MMDB: 2009/12
Experimental Method:
x-ray diffraction
Resolution: 2.5  Å
Source Organism:
Similar Structures:
Biological Unit for 3HJT: monomeric; determined by author and by software (PISA)
Molecular Components in 3HJT
Label Count Molecule
Protein (1 molecule)
1
LMB
Molecule annotation
Chemical (1 molecule)
1
1
* Click molecule labels to explore molecular sequence information.

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