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Updated: Feb 15, 2026
From Constructs to Crystals – Towards Structure Determination of β-barrel Outer Membrane Proteins
Published on: July 4, 2016
Crystal structure of the outer membrane protein OmpU from Vibrio cholerae at 2.2 Å resolution
Huanyu Li1, Weijiao Zhang1, Changjiang Dong1
1Biomedical Research Centre, Norwich Medical School, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, England.
Abstract:
Vibrio cholerae causes a severe disease that kills thousands of people annually. The outer membrane protein OmpU is the most abundant outer membrane protein in V. cholerae, and has been identified as an important virulence factor that is involved in host-cell interaction and recognition, as well as being critical for the survival of the pathogenic V. cholerae in the host body and in harsh environments. The mechanism of these processes is not well understood owing to a lack of the structure of V. cholerae OmpU. Here, the crystal structure of the V. cholerae OmpU trimer is reported to a resolution of 2.2 Å. The protomer forms a 16-β-stranded barrel with a noncanonical N-terminal coil located in the lumen of the barrel that consists of residues Gly32-Ser42 and is observed to participate in forming the second gate in the pore. By mapping the published functional data onto the OmpU structure, the OmpU structure reinforces the notion that the long extracellular loop L4 with a β-hairpin-like motif may be critical for host-cell binding and invasion, while L3, L4 and L8 are crucially implicated in phage recognition by V. cholerae.
Insights
The crystal structure of Vibrio cholerae outer membrane protein OmpU was determined. This structure reveals OmpU
Area of Science:
- Microbiology
- Structural Biology
- Biochemistry
Background:
- Vibrio cholerae infection causes significant global mortality.
- Outer membrane protein U (OmpU) is a key virulence factor in V. cholerae, essential for host interaction and survival.
- Understanding OmpU's structure is crucial for elucidating its function in pathogenesis.
Purpose of the Study:
- To determine the high-resolution crystal structure of the V. cholerae OmpU trimer.
- To provide structural insights into OmpU's role in host-cell interaction and phage recognition.
Main Methods:
- X-ray crystallography was used to determine the structure of V. cholerae OmpU.
- The crystal structure was resolved to a resolution of 2.2 Å.
- Published functional data was mapped onto the determined OmpU structure.
Main Results:
- The V. cholerae OmpU trimer forms a 16-β-stranded barrel structure.
- A noncanonical N-terminal coil within the barrel lumen acts as a second gate in the pore.
- Extracellular loops L3, L4, and L8 are implicated in phage recognition, while L4 may be critical for host-cell binding.
Conclusions:
- The determined OmpU structure provides a molecular basis for its functions in V. cholerae pathogenesis.
- Structural insights support OmpU's role in host-cell interactions and phage binding.
- Further research can utilize this structure to develop targeted interventions against V. cholerae.
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