5UK6

Structure of Anabaena Sensory Rhodopsin Determined by Solid State NMR Spectroscopy and DEER

Summary for 5UK6

• Entry DOI: 10.2210/pdb5uk6/pdb
• NMR Information: BMRB: 18595
• Descriptor: Bacteriorhodopsin (1 entity in total)
• Functional Keywords: anabeana sensory rhodopsin, trimer, seven-transmembrane proteins, signaling protein
• Biological source: Nostoc sp. (strain PCC 7120 / SAG 25.82 / UTEX 2576)
• Total number of polymer chains: 3
• Total formula weight: 82536.79

Authors

Milikisiyants, S.,Wang, S.,Munro, R.A.,Donohue, M.,Ward, M.E.,Brown, L.S.,Smirnova, T.I.,Ladizhansky, V.,Smirnov, A.I. (deposition date: 2017-01-20, release date: 2017-05-31, Last modification date: 2020-01-08)

Primary citation

Milikisiyants, S.,Wang, S.,Munro, R.A.,Donohue, M.,Ward, M.E.,Bolton, D.,Brown, L.S.,Smirnova, T.I.,Ladizhansky, V.,Smirnov, A.I.
Oligomeric Structure of Anabaena Sensory Rhodopsin in a Lipid Bilayer Environment by Combining Solid-State NMR and Long-range DEER Constraints.
J. Mol. Biol., 429:1903-1920, 2017

PubMed Abstract: Oligomerization of membrane proteins is common in nature. Here, we combine spin-labeling double electron-electron resonance (DEER) and solid-state NMR (ssNMR) spectroscopy to refine the structure of an oligomeric integral membrane protein, Anabaena sensory rhodopsin (ASR), reconstituted in a lipid environment. An essential feature of such a combined approach is that it provides structural distance restraints spanning a range of ca 3-60Å while using the same sample preparation (i.e., mutations, paramagnetic labeling, and reconstitution in lipid bilayers) for both ssNMR and DEER. Direct modeling of the multispin effects on DEER signal allowed for the determination of the oligomeric order and for obtaining long-range DEER distance restraints between the ASR trimer subunits that were used to refine the ssNMR structure of ASR. The improved structure of the ASR trimer revealed a more compact packing of helices and side chains at the intermonomer interface, compared to the structure determined using the ssNMR data alone. The extent of the refinement is significant when compared with typical helix movements observed for the active states of homologous proteins. Our combined approach of using complementary DEER and NMR measurements for the determination of oligomeric structures would be widely applicable to membrane proteins where paramagnetic tags can be introduced. Such a method could be used to study the effects of the lipid membrane composition on protein oligomerization and to observe structural changes in protein oligomers upon drug, substrate, and co-factor binding.

PubMed: 28501588
DOI: 10.1016/j.jmb.2017.05.005

Experimental method

SOLID-STATE NMR