title: Crystal structure of YaeT: conformational flexibility and substrate recognition.
abstract: The envelope of Gram-negative bacteria consists of inner and outer membranes surrounding the peptidoglycan wall. The outer membrane (OM) is rich in integral membrane proteins (OMPs), which have a characteristic beta barrel domain embedded in the OM. The Omp85 family of proteins, ubiquitous among Gram-negative bacteria and also present in chloroplasts and mitochondria, is required for folding and insertion of OMPs into the outer membrane. Bacterial Omp85 proteins are characterized by a periplasmic domain containing five repeats of polypeptide transport-associated (POTRA) motifs. Here we report the crystal structure of a periplasmic fragment of YaeT (the Escherichia coli Omp85) containing the first four POTRA domains in an extended conformation consistent with recent solution X-ray scattering data. Analysis of the YaeT structure reveals conformational flexibility around a hinge point between POTRA2 and 3 domains. The structure's implications for substrate binding and folding mechanisms are also discussed.
authors.affiliation: Department of Chemistry and Biochemistry, University of Colorado at Boulder, Boulder, CO 80309, USA.
authors.forename: Petia Z
authors.initials: PZ
authors.lastname: Gatzeva-Topalova
authors.forename: Troy A
authors.initials: TA
authors.lastname: Walton
authors.forename: Marcelo C
authors.initials: MC
authors.lastname: Sousa
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D003460:Crystallization; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D057927:Hydrophobic and Hydrophilic Interactions; D008958:Models, Molecular; D019897:Periplasm / Q000737:chemistry; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D013379:Substrate Specificity
chemical_list: D001425:Bacterial Outer Membrane Proteins; C503914:BamA protein, E coli; D029968:Escherichia coli Proteins