DECIPHERING THE ROLE OF YIDC IN BACTERIAL MEMBRANE PROTEIN INSERTION

 
 
 
 

DECIPHERING THE ROLE OF YIDC IN BACTERIAL MEMBRANE PROTEIN INSERTION

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dc.contributor.advisor Dalbey, Ross E en_US
dc.contributor.author Chen, Minyong en_US
dc.date.accessioned 2008-07-07T18:51:03Z
dc.date.available 2008-07-07T18:51:03Z
dc.date.created 2002 en_US
dc.date.issued 2008-07-07T18:51:03Z
dc.identifier.uri http://rave.ohiolink.edu/etdc/view?acc_num=osu1039101039 en_US
dc.identifier.uri http://hdl.handle.net/2374.OX/5058
dc.description The Sec complex is the major translocase to mediate membrane protein insertion in bacteria, but there exists some proteins whose insertion is independent of the Sec complex. In year 2000, YidC was discovered that is essential for insertion of proteins into membranes in bacteria, especially for the Sec-independent proteins. Chapter 1 is an in-depth review about YidC in membrane protein assembly. In Chapter 2, we found YidC interacts with leader peptidase during its membrane insertion using crosslinking techniques. These data combined with the in vivo depletion study of YidC (James Samuelson’s dissertation, 2000) provide strong evidence to support YidC is a translocase component in bacteria. In Chapter 3, I report that the Sec-independent Pf3 coat protein requires YidC for insertion into the membrane. Using photocrosslinking techniques, we find that Pf3 coat interacts strongly with YidC only after its transmembrane segment is fully exposed outside the ribosome tunnel. Interaction between Pf3 coat and YidC occurs even when the proton motive force does not function on Pf3 coat. Our study demonstrates that YidC can directly interact with a Sec-independent membrane protein and its role is to fold the Pf3 protein into a transmembrane configuration. In Chapter 4, we found incorporation of site-specific protease sites into YidC results in YidC temperature-sensitive (ts) or cold-sensitive (cs) mutants. The YidC ts and cs strains were then constructed. The membrane insertion of the Sec-independent M13 procoat protein is inhibited in YidC ts strains when the cells were grown at 42 oC for 20 minutes. This provides the strongest evidence thus far that YidC plays a direct role in membrane protein insertion. Using the cs YidC strain, we find the insertion of the Sec-dependent leader peptidase is inhibited at 25 oC, whereas the insertion of M13 procoat is nearly normal. The cs YidC mutant shows a reduced interaction with the Sec machinery. These data suggest that the cold-sensitive YidC mutant is blocked in the Sec-related function, while its activity for inserting procoat is functioning almost normally. These properties of the cold-sensitive mutant strongly support the idea that YidC can function alone or with the Sec machinery. en_US
dc.format application/pdf en_US
dc.format 157p. en_US
dc.rights unrestricted en_US
dc.rights Copyright and permissions information available at the source archive en_US
dc.subject YidC en_US
dc.subject membrane protein en_US
dc.subject membrane protein insertion en_US
dc.subject Oxa1 en_US
dc.subject Alb3 en_US
dc.subject SecYEG en_US
dc.subject SecDFYajC en_US
dc.subject temperature sensitive en_US
dc.subject cold sensitive en_US
dc.subject photocrosslinking en_US
dc.subject Pf3 coat en_US
dc.subject M13 procoat en_US
dc.subject leader peptidase en_US
dc.title DECIPHERING THE ROLE OF YIDC IN BACTERIAL MEMBRANE PROTEIN INSERTION en_US
dc.type Electronic Thesis or Dissertation en_US
dc.degree.name PhD en_US
dc.degree.level doctoral en_US
dc.degree.discipline Ohio State Biochemistry Program en_US
dc.degree.grantor Ohio State University en_US
dc.contributor.publisher Ohio State University / OhioLINK en_US

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