N-terminomics identifies widespread endoproteolysis and novel methionine excision in a genome-reduced bacterial pathogen.
Sci Rep
; 7(1): 11063, 2017 09 11.
Article
in En
| MEDLINE
| ID: mdl-28894154
ABSTRACT
Proteolytic processing alters protein function. Here we present the first systems-wide analysis of endoproteolysis in the genome-reduced pathogen Mycoplasma hyopneumoniae. 669 N-terminal peptides from 164 proteins were identified, demonstrating that functionally diverse proteins are processed, more than half of which 75 (53%) were accessible on the cell surface. Multiple cleavage sites were characterised, but cleavage with arginine in P1 predominated. Putative functions for a subset of cleaved fragments were assigned by affinity chromatography using heparin, actin, plasminogen and fibronectin as bait. Binding affinity was correlated with the number of cleavages in a protein, indicating that novel binding motifs are exposed, and protein disorder increases, after a cleavage event. Glyceraldehyde 3-phosphate dehydrogenase was used as a model protein to demonstrate this. We define the rules governing methionine excision, show that several aminopeptidases are involved, and propose that through processing, genome-reduced organisms can expand protein function.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Bacterial Proteins
/
Proteome
/
Proteomics
Language:
En
Journal:
Sci Rep
Year:
2017
Document type:
Article
Affiliation country:
Australia