A conserved glycine residue of trimeric autotransporter domains plays a key role in Yersinia adhesin A autotransport.
The Yersinia adhesin A (YadA) is a trimeric autotransporter adhesin of enteric yersiniae. It consists of three major domains: a head mediating adherence to host cells, a stalk involved in serum resistance, and an anchor that forms a membrane pore and is responsible for the autotransport function. The anchor contains a glycine residue, nearly invariant throughout trimeric autotransporter adhesins, that faces the pore lumen. To address the role of this glycine, we replaced it with polar amino acids of increasing side chain size and expressed wild-type and mutant YadA in Escherichia coli. The mutations did not impair the YadA-mediated adhesion to collagen and to host cells or the host cell cytokine production, but they decreased the expression levels and stability of YadA trimers with increasing side chain size. Likewise, autoagglutination and resistance to serum were decreased in these mutants. We found that the periplasmic protease DegP is involved in the degradation of YadA and that in an E. coli degP deletion strain, mutant versions of YadA were expressed almost to wild-type levels. We conclude that the conserved glycine residue affects both the export and the stability of YadA and consequently some of its putative functions in pathogenesis.
Grosskinsky
Ulrike
U
Institut für Medizinische Mikrobiologie und Hygiene, Universitätsklinikum Tübingen, Tübingen, Germany.
Schütz
Monika
M
Fritz
Michaela
M
Schmid
Yvonne
Y
Lamparter
Marina C
MC
Szczesny
Pawel
P
Lupas
Andrei N
AN
Autenrieth
Ingo B
IB
Linke
Dirk
D
D018829:Adhesins, Bacterial / Q000235:genetics / Q000378:metabolism*; D019943:Amino Acid Substitution / Q000235:genetics; D001422:Bacterial Adhesion / Q000235:genetics / Q000502:physiology; D003094:Collagen / Q000378:metabolism; D017124:Conserved Sequence; D004926:Escherichia coli / Q000235:genetics; D017353:Gene Deletion; D015870:Gene Expression; D005998:Glycine / Q000235:genetics / Q000502:physiology*; D006367:HeLa Cells; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D050296:Microbial Viability; D016297:Mutagenesis, Site-Directed; D033903:Periplasmic Proteins / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D021381:Protein Transport; D012697:Serine Endopeptidases / Q000235:genetics / Q000378:metabolism; D015610:Serum Bactericidal Test; D015007:Yersinia / Q000235:genetics / Q000378:metabolism*
D018829:Adhesins, Bacterial; D006360:Heat-Shock Proteins; D033903:Periplasmic Proteins; C064832:YadA protein, Yersinia; D003094:Collagen; C061682:DegP protease; D012697:Serine Endopeptidases; D005998:Glycine