Abstract:
:Flagellin is the subunit of the bacterial filament, the micrometer-long propeller of a bacterial flagellum. The protein is believed to undergo unfolding for transport through the channel of the filament and to refold in a chamber at the end of the channel before being assembled into the growing filament. We report a thermal unfolding simulation study of S. typhimurium flagellin in aqueous solution as an attempt to gain atomic-level insight into the refolding process. Each molecule comprises two filament-core domains {D0, D1} and two hypervariable-region domains {D2, D3}. D2 can be separated into subdomains D2a and D2b. We observed a similar unfolding order of the domains as reported in experimental thermal denaturation. D2a and D3 exhibited high thermal stability and contained persistent three-stranded beta-sheets in the denatured state which could serve as folding cores to guide refolding. A recent mutagenesis study on flagellin stability seems to suggest the importance of the folding cores. Using crude size estimates, our data suggests that the chamber might be large enough for either denatured hypervariable-region domains or filament-core domains, but not whole flagellin; this implicates a two-staged refolding process.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Chng CP,Kitao Adoi
10.1529/biophysj.107.123927subject
Has Abstractpub_date
2008-05-15 00:00:00pages
3858-71issue
10eissn
0006-3495issn
1542-0086pii
S0006-3495(08)70388-6journal_volume
94pub_type
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