title: High resolution solid-state NMR spectroscopy of the Yersinia pestis outer membrane protein Ail in lipid membranes.
abstract: The outer membrane protein Ail (Adhesion invasion locus) is one of the most abundant proteins on the cell surface of Yersinia pestis during human infection. Its functions are expressed through interactions with a variety of human host proteins, and are essential for microbial virulence. Structures of Ail have been determined by X-ray diffraction and solution NMR spectroscopy, but those samples contained detergents that interfere with functionality, thus, precluding analysis of the structural basis for Ail's biological activity. Here, we demonstrate that high-resolution solid-state NMR spectra can be obtained from samples of Ail in detergent-free phospholipid liposomes, prepared with a lipid to protein molar ratio of 100. The spectra, obtained with13C or1H detection, have very narrow line widths (0.40-0.60 ppm for13C, 0.11-0.15 ppm for1H, and 0.46-0.64 ppm for15N) that are consistent with a high level of sample homogeneity. The spectra enable resonance assignments to be obtained for N, CO, CA and CB atomic sites from 75 out of 156 residues in the sequence of Ail, including 80% of the transmembrane region. The1H-detected solid-state NMR1H/15N correlation spectra obtained for Ail in liposomes compare very favorably with the solution NMR1H/15N TROSY spectra obtained for Ail in nanodiscs prepared with a similar lipid to protein molar ratio. These results set the stage for studies of the molecular basis of the functional interactions of Ail with its protein partners from human host cells, as well as the development of drugs targeting Ail.
authors.affiliation: Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA, 92037, USA.
authors.forename: Yong
authors.initials: Y
authors.lastname: Yao
authors.affiliation: Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA, 92037, USA.
authors.forename: Samit Kumar
authors.initials: SK
authors.lastname: Dutta
authors.affiliation: Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0307, USA.
authors.forename: Sang Ho
authors.initials: SH
authors.lastname: Park
authors.affiliation: Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0307, USA.
authors.forename: Ratan
authors.initials: R
authors.lastname: Rai
authors.affiliation: Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA, 92037, USA.
authors.forename: L Miya
authors.initials: LM
authors.lastname: Fujimoto
authors.affiliation: Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA, 92037, USA.
authors.forename: Andrey A
authors.initials: AA
authors.lastname: Bobkov
authors.affiliation: Department of Chemistry and Biochemistry, University of California San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0307, USA.
authors.forename: Stanley J
authors.initials: SJ
authors.lastname: Opella
authors.affiliation: Sanford Burnham Prebys Medical Discovery Institute, 10901 North Torrey Pines Road, La Jolla, CA, 92037, USA. fmarassi@sbp.edu.
authors.forename: Francesca M
authors.initials: FM
authors.lastname: Marassi
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D066241:Carbon-13 Magnetic Resonance Spectroscopy; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008563:Membrane Lipids / Q000737:chemistry*; D019906:Nuclear Magnetic Resonance, Biomolecular; D066244:Proton Magnetic Resonance Spectroscopy; D012996:Solutions; D037521:Virulence Factors / Q000737:chemistry*
chemical_list: C526543:Ail protein, Yersinia pestis; D001425:Bacterial Outer Membrane Proteins; D008563:Membrane Lipids; D012996:Solutions; D037521:Virulence Factors
keywords: Ail; Magic angle spinning; Membrane protein; Solid-state NMR; Yersinia pestis