Back to Search
Start Over
Characterization of a Novel Intramolecular Chaperone Domain Conserved in Endosialidases and Other Bacteriophage Tail Spike and Fiber Proteins.
- Source :
-
Journal of Biological Chemistry . 2/2/2007, Vol. 282 Issue 5, p2821-2831. 11p. 7 Diagrams, 2 Charts, 2 Graphs. - Publication Year :
- 2007
-
Abstract
- Folding and assembly of endosialidases, the trimeric tail spike proteins of Escherichia coli K1-specific bacteriophages, crucially depend on their C-terminal domain (CTD). Homologous CTDs were identified in phage proteins belonging to three different protein families: neck appendage proteins of several Bacillus phages, L-shaped tail fibers of coliphage T5, and K5 lyases, the tail spike proteins of phages infecting E. coli K5. By analyzing a representative of each family, we show that in all cases, the CTD is cleaved off after a strictly conserved serine residue and alanine substitution prevented cleavage. Further structural and functional analyses revealed that (i) CTDs are autonomous domains with a high α-helical content; (ii) proteolytically released CTDs assemble into hexamers, which are most likely dimers of trimers; (iii) highly conserved amino acids within the CTD are indispensable for CTD-mediated folding and complex formation; (iv) CTDs can be exchanged between proteins of different families; and (v) proteolytic cleavage is essential to stabilize the native protein complex. Data obtained for full-length and proteolytically processed endosialidase variants suggest that release of the CTD increases the unfolding barrier, trapping the mature trimer in a kinetically stable conformation. In summary, we characterize the CTD as a novel C-terminal chaperone domain, which assists folding and assembly of unrelated phage proteins. [ABSTRACT FROM AUTHOR]
- Subjects :
- *MOLECULAR chaperones
*BACTERIOPHAGES
*PROTEINS
*ESCHERICHIA coli
*ALANINE
Subjects
Details
- Language :
- English
- ISSN :
- 00219258
- Volume :
- 282
- Issue :
- 5
- Database :
- Academic Search Index
- Journal :
- Journal of Biological Chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 24252532
- Full Text :
- https://doi.org/10.1074/jbc.M609543200