4WL1

Structure of WzzE Polysaccharide Co-polymerase

Summary for 4WL1

• Entry DOI: 10.2210/pdb4wl1/pdb
• Descriptor: Lipopolysaccharide biosynthesis protein WzzE (1 entity in total)
• Functional Keywords: eca, enterobacterial common antigen, chain length regulator, polysaccharide co-polymerase, membrane protein
• Biological source: Escherichia coli
• Cellular location: Cell inner membrane ; Multi-pass membrane protein : P0AG01
• Total number of polymer chains: 32
• Total formula weight: 1296160.51

Authors

Kalynych, S.,Cherney, M.,Cygler, M. (deposition date: 2014-10-05, release date: 2014-10-29, Last modification date: 2023-09-27)

Primary citation

Kalynych, S.,Cherney, M.,Bostina, M.,Rouiller, I.,Cygler, M.
Quaternary structure of WzzB and WzzE polysaccharide copolymerases.
Protein Sci., 24:58-69, 2015

PubMed Abstract: Bacteria have evolved cellular control mechanisms to ensure proper length specification for surface-bound polysaccharides. Members of the Polysaccharide Copolymerase (PCP) family are central to this process. PCP-1 family members are anchored to the inner membrane through two transmembrane helices and contain a large periplasm-exposed domain. PCPs are known to form homooligomers but their exact stoichiometry is controversial in view of conflicting structural and biochemical data. Several prior investigations addressing this question indicated a nonameric, hexameric, or tetrameric organization of several PCP-1 family members. In this work, we gathered additional evidence that E.coli WzzB and WzzE PCPs form octameric homo-oligomeric complexes. Detergent-solubilized PCPs were purified to homogeneity and subjected to blue native gel analysis, which indicated the presence of a predominant high-molecular product of over 500 kDa in mass. Molecular mass of WzzE and WzzB-detergent oligomers was estimated to be 550 kDA by size-exclusion coupled to multiangle laser light scattering (SEC-MALLS). Oligomeric organization of purified WzzB and WzzE was further investigated by negative stain electron microscopy and by X-ray crystallography, respectively. Analysis of EM-derived molecular envelope of WzzB indicated that the full-length protein is composed of eight protomers. Crystal structure of LDAO-solubilized WzzE was solved to 6 Å resolutions and revealed its octameric subunit stoichiometry. In summary, we identified a possible biological unit utilized for the glycan chain length determination by two PCP-1 family members. This provides an important step toward further unraveling of the mechanistic basis of chain length control of the O-antigen and the enterobacterial common antigen.

PubMed: 25307743
DOI: 10.1002/pro.2586

Experimental method

X-RAY DIFFRACTION (5.989 Å)