Specificity and structural characterization of the PDZ domain from DegS, an extracytoplasmic E. coli protease

DegS is a membrane-bound bacterial protease that is involved in the extracytoplasmic-stress response. The C-terminal domain has limited homology to PDZ domains and was thought to be involved in regulation or substrate recognition. A model of this PDZ domain was generated from NMR solution studies and homology modeling. Peptide selection studies identified the sequence Tyr-Tyr-Phe (YYF) as a C-terminal motif that binds to the PDZ domain. Possible targets were identified including many of the outer-membrane proteins (OMPs), which contain both a conserved terminal YxF and internal YYF sequences. The binding of the DegS PDZ domain to a YYF peptide and OMP derivatives were confirmed using microcalorimetry. Because stress signaling can be triggered by over-expression of some of the outer-membrane proteins, I propose that DegS may receive a signal from unassembled OMPs and transmit it to the aE transcription factor by increasing proteolysis of RseA.

Name thesis:degree_name

Doctoral

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Biology

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2002

Author dc:creator

• Walsh, Nathan P. (Nathan Peter), 1973-

Advisor dc:contributor.advisor

• Robert T. Sauer.

• Biology.

Statement dc:rights

• MIT theses may be protected by copyright. Please reuse MIT thesis content according to the MIT Libraries Permissions Policy, which is available through the URL provided.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Handle dc:identifier.uri

https://hdl.handle.net/1721.1/157629

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/157629