3HJT

Structure of laminin binding protein (Lmb) of Streptococcus agalactiae A bifunctional protein with adhesin and metal transporting activity

Summary for 3HJT

• Entry DOI: 10.2210/pdb3hjt/pdb
• Descriptor: Lmb, ZINC ION (3 entities in total)
• Functional Keywords: adhesin, metal transporter, surface protein, laminin binding, atp binding cassette, sbps (solute binding proteins), transport, transport protein, cell adhesion
• Biological source: Streptococcus agalactiae
• Total number of polymer chains: 2
• Total formula weight: 64407.67

Authors

Ponnuraj, K.,Ragunathan, P.,Spellerberg, B. (deposition date: 2009-05-22, release date: 2009-12-01, Last modification date: 2023-11-01)

Primary citation

Ragunathan, P.,Spellerberg, B.,Ponnuraj, K.
Structure of laminin-binding adhesin (Lmb) from Streptococcus agalactiae
Acta Crystallogr.,Sect.D, 65:1262-1269, 2009

PubMed 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.

PubMed: 19966412
DOI: 10.1107/S0907444909038359

Experimental method

X-RAY DIFFRACTION (2.5 Å)