School of Life Sciences
 

Christopher Penfold

Lecturer and Course Director for MSc in Molecular Medical Microbiology, Faculty of Medicine & Health Sciences

Contact

Expertise Summary

Normal 0 false false false EN-GB X-NONE X-NONE MicrosoftInternetExplorer4 st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Colicins are protein antibiotics produced by strains of Escherichia coli to kill non-producing strains of the same organims presumably as a method of competitive inhibition. Colicins molecules have three domains that are intrinsically linked to deliver the colicin from the outer membrane to the cytotoxic site of action; either the cytoplasmic membrane or the cytosol. The colicin system continues to generate exciting data about this amazing biological system that addresses several fundamental problems that are poorly understood at the molecular level: (1) Early steps in filamentous bacteriophage infection. Many phages share the same translocation machinery with colicins and possibly the same mechanism for traversing the OM; (2) Host protein function. The functions of host systems that are subverted by colicins such as the Tol-Pal complex remain unresolved even though they are important and ubiquitous in Gram-negative bacteria; (3) Protein recruitment by natively disordered regions (NDRs). NDRs are functionally important in proteins throughout the three kingdoms of life as well as being implicated in cancer, amyloid diseases and bacterial pathogenesis. We have discovered novel recruitment mechanisms used by enzymatic colicin NDRs to bind soluble and membrane-bound proteins in preparation for cellular import; (4) Protein translocation across membranes. How proteins are translocated across membrane barriers is a key issue in the biological and biomedical sciences. A quarter of the E. coli proteome is extracytoplasmic, targeted to a final destination by short, canonical N-terminal sequences that for the most part direct them either to the general secretory or Tat pathway machines. Nuclease colicins are also targeted but in the opposite direction, across both membrane barriers and by a mechanism that is insensitive to the structure of the imported enzyme.

Teaching Summary

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Research Summary

Bacteriocins are protein antibiotics produced by strains of bacteria that are active against related bacteria. We are particularly interested in a group of bacteriocins called colicins that are… read more

Recent Publications

School of Life Sciences

University of Nottingham
Medical School
Queen's Medical Centre
Nottingham NG7 2UH

e: life-sciences@nottingham.ac.uk
t: +44 (0)115 823 0141
f: +44 (0)115 823 0142