Structrure refinement of (3465) bacterioopsin from NMR data in solution

I. V. Maslennikov, A. L. Lomize, A. S. Arseniev

M. M. Shemyakin Institute of Bioorganic Chemistry, Academy of Sciences of the USSR, Moscow

Abstract: The spatial structure of a synthetic peptide, an analogue of the membrane spanning segment B (residues 3465) of bacterioopsin from Halobacterium halobium, has been refined. Backbone torsion angles were derived from intensities of short-range interproton NOEs. These, together with a complete set of the NOEs integral intensities formed the basis for the three-dimensional structure refinement by the energy minimization with consideration of NOE penalty functions. Analysis indicates the right-handed α-helical conformation of segment B extending from Asp-38 to Tyr-64 with a kink of the helical axis (27) at Pro-50. The most stable region with an average root-mean-square deviation of 0.43 A between the backbone atoms includes residues 4260 in six energy refined structures. The N-terminal part of segment B (residues 3437) has no ordered conformation. The inferred structure is in close agreement with the electron cryomicroscopy structure of bacteriorhodopsin, differing from it in conformations of most of the side chains.

Russian Journal of Bioorganic Chemistry 1991, 17 (11):1456-1469

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