Internalins from the human pathogen Listeria monocytogenes combine three distinct folds into a contiguous internalin domain.
Listeria monocytogenes is an opportunistic, food-borne human and animal pathogen. Host cell invasion requires the action of the internalins A (InlA) and B (InlB), which are members of a family of listerial cell-surface proteins. Common to these proteins are three distinctive N-terminal domains that have been shown to direct host cell-specific invasion for InlA and InlB. Here, we present the high-resolution crystal structures of these domains present in InlB and InlH, and show that they constitute a single "internalin domain". In this internalin domain, a central LRR region is flanked contiguously by a truncated EF-hand-like cap and an immunoglobulin (Ig)-like fold. The extended beta-sheet, resulting from the distinctive fusion of the LRR and the Ig-like folds, constitutes an adaptable concave interaction surface, which we propose is responsible for the specific recognition of the host cellular binding partners during infection.
Schubert
W D
WD
Department of Structural Biology, German Research Center for Biotechnology, Braunschweig.
Göbel
G
G
Diepholz
M
M
Darji
A
A
Kloer
D
D
Hain
T
T
Chakraborty
T
T
Wehland
J
J
Domann
E
E
Heinz
D W
DW
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D018360:Crystallography, X-Ray; D020832:EF Hand Motifs; D006801:Humans; D007136:Immunoglobulins / Q000737:chemistry; D007930:Leucine / Q000378:metabolism; D008089:Listeria monocytogenes / Q000737:chemistry* / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology; D008088:Listeriosis / Q000382:microbiology; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008954:Models, Biological; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D020449:Repetitive Sequences, Amino Acid; D016415:Sequence Alignment
D001426:Bacterial Proteins; D007136:Immunoglobulins; D008565:Membrane Proteins; C095768:inlB protein, Listeria monocytogenes; C116311:internalin H protein, Listeria monocytogenes; D007930:Leucine