TY - JOUR
T1 - X-ray Crystal Structures of the Influenza M2 Proton Channel Drug-Resistant V27A Mutant Bound to a Spiro-Adamantyl Amine Inhibitor Reveal the Mechanism of Adamantane Resistance
AU - Thomaston, Jessica L.
AU - Konstantinidi, Athina
AU - Liu, Lijun
AU - Lambrinidis, George
AU - Tan, Jingquan
AU - Caffrey, Martin
AU - Wang, Jun
AU - Degrado, William F.
AU - Kolocouris, Antonios
N1 - Funding Information:
J.L.T. and W.F.D. were supported by National Institutes of Health (NIH) Grants R35-GM122603 and R01-GM117593. J.W. was supported by NIH Grant R33-AI119187. J.T. and M.C. were supported by Science Foundation Ireland Grants 12/IA/1255 and 16/IA/4435.
Funding Information:
A. Kolocouris is grateful to Chiesi Hellas for supporting the Ph.D. work of A. Konstantinidi. Use of the LCP crystallization robot was made possible by National Center for Research Resources Grant 1S10RR027234-01. The authors thank Pil Seok Chae (Hanyang University, Seoul, South Korea) for providing MNG detergent for crystallization trials. J.T. and M.C. thank David Aragão and Valerie Pye for help with diffraction measurements and structure determination using the first ever crystals of the M2 V27A TM domain. Data collection was carried out at ALS 8.3.1. Beamline 8.3.1 at the Advanced Light Source is operated by the University of California Office of the President, supported by Multicampus Research Programs and Initiatives Grant MR-15-328599 and National Institute of General Medical Sciences Grants P30 GM124169 and R01 GM124149. The authors thank George Meigs and James Holton at ALS 8.3.1 for support during data collection.
Publisher Copyright:
Copyright © 2020 American Chemical Society.
PY - 2020/2/4
Y1 - 2020/2/4
N2 - The V27A mutation confers adamantane resistance on the influenza A matrix 2 (M2) proton channel and is becoming more prevalent in circulating populations of influenza A virus. We have used X-ray crystallography to determine structures of a spiro-adamantyl amine inhibitor bound to M2(22-46) V27A and also to M2(21-61) V27A in the Inwardclosed conformation. The spiro-adamantyl amine binding site is nearly identical for the two crystal structures. Compared to the M2 "wild type" (WT) with valine at position 27, we observe that the channel pore is wider at its N-terminus as a result of the V27A mutation and that this removes V27 side chain hydrophobic interactions that are important for binding of amantadine and rimantadine. The spiro-adamantyl amine inhibitor blocks proton conductance in the WT and V27A mutant channels by shifting its binding site in the pore depending on which residue is present at position 27. Additionally, in the structure of the M2(21-61) V27A construct, the C-terminus of the channel is tightly packed relative to that of the M2(22-46) construct. We observe that residues Asp44, Arg45, and Phe48 face the center of the channel pore and would be well-positioned to interact with protons exiting the M2 channel after passing through the His37 gate. A 300 ns molecular dynamics simulation of the M2(22-46) V27A-spiro-adamantyl amine complex predicts with accuracy the position of the ligands and waters inside the pore in the X-ray crystal structure of the M2(22-46) V27A complex.
AB - The V27A mutation confers adamantane resistance on the influenza A matrix 2 (M2) proton channel and is becoming more prevalent in circulating populations of influenza A virus. We have used X-ray crystallography to determine structures of a spiro-adamantyl amine inhibitor bound to M2(22-46) V27A and also to M2(21-61) V27A in the Inwardclosed conformation. The spiro-adamantyl amine binding site is nearly identical for the two crystal structures. Compared to the M2 "wild type" (WT) with valine at position 27, we observe that the channel pore is wider at its N-terminus as a result of the V27A mutation and that this removes V27 side chain hydrophobic interactions that are important for binding of amantadine and rimantadine. The spiro-adamantyl amine inhibitor blocks proton conductance in the WT and V27A mutant channels by shifting its binding site in the pore depending on which residue is present at position 27. Additionally, in the structure of the M2(21-61) V27A construct, the C-terminus of the channel is tightly packed relative to that of the M2(22-46) construct. We observe that residues Asp44, Arg45, and Phe48 face the center of the channel pore and would be well-positioned to interact with protons exiting the M2 channel after passing through the His37 gate. A 300 ns molecular dynamics simulation of the M2(22-46) V27A-spiro-adamantyl amine complex predicts with accuracy the position of the ligands and waters inside the pore in the X-ray crystal structure of the M2(22-46) V27A complex.
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U2 - 10.1021/acs.biochem.9b00971
DO - 10.1021/acs.biochem.9b00971
M3 - Article
C2 - 31894969
AN - SCOPUS:85078667564
VL - 59
SP - 627
EP - 634
JO - Biochemistry
JF - Biochemistry
SN - 0006-2960
IS - 4
ER -