Journal article
The Anti-sigma Factor RsiV Is a Bacterial Receptor for Lysozyme: Co-crystal Structure Determination and Demonstration That Binding of Lysozyme to RsiV Is Required for σV Activation
PLoS genetics, Vol.12(9), pp.e1006287-e1006287
09/2016
DOI: 10.1371/journal.pgen.1006287
PMCID: PMC5014341
PMID: 27602573
Abstract
σ factors provide RNA polymerase with promoter specificity in bacteria. Some σ factors require activation in order to interact with RNA polymerase and transcribe target genes. The Extra-Cytoplasmic Function (ECF) σ factor, σV, is encoded by several Gram-positive bacteria and is specifically activated by lysozyme. This activation requires the proteolytic destruction of the anti-σ factor RsiV via a process of regulated intramembrane proteolysis (RIP). In many cases proteases that cleave at site-1 are thought to directly sense a signal and initiate the RIP process. We previously suggested binding of lysozyme to RsiV initiated the proteolytic destruction of RsiV and activation of σV. Here we determined the X-ray crystal structure of the RsiV-lysozyme complex at 2.3 Å which revealed that RsiV and lysozyme make extensive contacts. We constructed RsiV mutants with altered abilities to bind lysozyme. We find that mutants that are unable to bind lysozyme block site-1 cleavage of RsiV and σV activation in response to lysozyme. Taken together these data demonstrate that RsiV is a receptor for lysozyme and binding of RsiV to lysozyme is required for σV activation. In addition, the co-structure revealed that RsiV binds to the lysozyme active site pocket. We provide evidence that in addition to acting as a sensor for the presence of lysozyme, RsiV also inhibits lysozyme activity. Thus we have demonstrated that RsiV is a protein with multiple functions. RsiV inhibits σV activity in the absence of lysozyme, RsiV binds lysozyme triggering σV activation and RsiV inhibits the enzymatic activity of lysozyme.
Details
- Title: Subtitle
- The Anti-sigma Factor RsiV Is a Bacterial Receptor for Lysozyme: Co-crystal Structure Determination and Demonstration That Binding of Lysozyme to RsiV Is Required for σV Activation
- Creators
- Jessica L Hastie - Department of Microbiology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of AmericaKyle B Williams - Department of Microbiology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of AmericaLindsey L Bohr - Department of Microbiology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of AmericaJon C Houtman - Department of Microbiology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of AmericaLokesh Gakhar - Department of Biochemistry & Protein Crystallography Facility, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of AmericaCraig D Ellermeier - Department of Microbiology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
- Resource Type
- Journal article
- Publication Details
- PLoS genetics, Vol.12(9), pp.e1006287-e1006287
- DOI
- 10.1371/journal.pgen.1006287
- PMID
- 27602573
- PMCID
- PMC5014341
- NLM abbreviation
- PLoS Genet
- ISSN
- 1553-7390
- eISSN
- 1553-7404
- Publisher
- Public Library Science
- Grant note
- R01 AI087834 / NIAID NIH HHS T32 AI007511 / NIAID NIH HHS
- Language
- English
- Date published
- 09/2016
- Academic Unit
- Microbiology and Immunology; Biochemistry and Molecular Biology; Medicine Administration; Internal Medicine
- Record Identifier
- 9984083274202771
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