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6349688 
Journal Article 
Proteins complexed to the P1 adhesin of Mycoplasma pneumoniae 
Layh-Schmitt, G; Podtelejnikov, A; Mann, M 
2000 
1 
Microbiology (Reading, England)
ISSN: 1350-0872
EISSN: 1465-2080 
146 ( Pt 3) 
3 
741-747 
English 
10746778 
WOS:000085895500021 
Adherence of Mycoplasma pneumoniae to host cells requires several mycoplasmal membrane proteins and cytoskeleton-like proteins in addition to the adhesin P1, a transmembrane protein of 170 kDa. To analyse interactions of the P1 adhesin with other membrane proteins or with cytoskeleton-like proteins, cross-linking studies were performed in vivo using the permeant reagent paraformaldehyde. The cross-linked protein complex was isolated by immunoaffinity chromatography, and proteins complexed to the P1 protein were identified by immunoblot analysis followed by high mass accuracy tryptic peptide mapping using matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). In addition to the P1 protein and a truncated form of the same protein, the adhesin-related 30 kDa protein, two membrane proteins of 40 and 90 kDa, the cytoskeleton-associated 65 kDa protein and two cytoskeleton-forming proteins, HMW1 and HMW3, were found to be components of the isolated protein complex. Furthermore, the cross-linked complex contained the chaperone DnaK and the E1alpha subunit of pyruvate dehydrogenase. In summary, it was shown that cytadherence-associated membrane proteins are located in close proximity to cytoskeleton-like proteins, suggesting a functional interaction between membrane and cytoskeleton-like proteins. DnaK might be involved in translocation of proteins from the cytoplasm to the membrane and pyruvate dehydrogenase might be a structural protein of the attachment organelle. 
Affinity chromatography; Cytoskeleton; Membrane proteins; Mass spectroscopy; Mycoplasma pneumoniae; adhesin P1/