4C47

Salmonella enterica trimeric lipoprotein SadB

Summary for 4C47

• Entry DOI: 10.2210/pdb4c47/pdb
• Related: 4C46
• Descriptor: INNER MEMBRANE LIPOPROTEIN (2 entities in total)
• Functional Keywords: cell adhesion, bacterial adhesion, membrane trafficking, membrane insertion, autotransport, polar core residues
• Biological source: SALMONELLA ENTERICA SUBSP. ENTERICA SEROVAR TYPHIMURIUM STR. LT2
• Total number of polymer chains: 3
• Total formula weight: 71197.08

Authors

Grin, I.,Linke, D.,Hartmann, M.D. (deposition date: 2013-09-02, release date: 2014-01-08, Last modification date: 2024-05-08)

Primary citation

Grin, I.,Hartmann, M.D.,Sauer, G.,Hernandez Alvarez, B.,Schutz, M.,Madlung, J.,Macek, B.,Felipe-Lopez, A.,Hensel, M.,Lupas, A.,Linke, D.
A Trimeric Lipoprotein Assists in Trimeric Autotransporter Biogenesis in Enterobacteria.
J.Biol.Chem., 289:7388-, 2014

PubMed Abstract: Trimeric autotransporter adhesins (TAAs) are important virulence factors of many Gram-negative bacterial pathogens. TAAs form fibrous, adhesive structures on the bacterial cell surface. Their N-terminal extracellular domains are exported through a C-terminal membrane pore; the insertion of the pore domain into the bacterial outer membrane follows the rules of β-barrel transmembrane protein biogenesis and is dependent on the essential Bam complex. We have recently described the full fiber structure of SadA, a TAA of unknown function in Salmonella and other enterobacteria. In this work, we describe the structure and function of SadB, a small inner membrane lipoprotein. The sadB gene is located in an operon with sadA; orthologous operons are only found in enterobacteria, whereas other TAAs are not typically associated with lipoproteins. Strikingly, SadB is also a trimer, and its co-expression with SadA has a direct influence on SadA structural integrity. This is the first report of a specific export factor of a TAA, suggesting that at least in some cases TAA autotransport is assisted by additional periplasmic proteins.

PubMed: 24369174
DOI: 10.1074/JBC.M113.513275

Experimental method

X-RAY DIFFRACTION (2.448 Å)