Deer mouse hemoglobin exhibits a lowered oxygen affinity owing to mobility of the E helix

Authors

Noriko Inoguchi, University of Nebraska-LincolnFollow
Jake R. Oshlo, bNebraska Wesleyan University
Chandrasekhar Natarajan, University of Nebraska-LincolnFollow
Roy E. Weber, Aarhus University, AarhusFollow
Angela Fago, Aarhus University
Jay F. Storz, University of Nebraska-LincolnFollow
Hideaki Moriyama, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

2013

Citation

Acta Cryst. (2013). F69, 393–398

doi:10.1107/S1744309113005708

Comments

Copyright 2013 International Union of Crystallography All rights reserved

Abstract

The deer mouse, Peromyscus maniculatus, exhibits altitude-associated variation in hemoglobin oxygen affinity. To examine the structural basis of this functional variation, the structure of the hemoglobin was solved. Recombinant hemoglobin was expressed in Escherichia coli and was purified by ion-exchange chromatography. Recombinant hemoglobin was crystallized by the hangingdrop vapor-diffusion method using polyethylene glycol as a precipitant. The obtained orthorhombic crystal contained two subunits in the asymmetric unit. The refined structure was interpreted as the aquo-met form. Structural comparisons were performed among hemoglobins from deer mouse, house mouse and human. In contrast to human hemoglobin, deer mouse hemoglobin lacks the hydrogen bond between α1Trp14 in the A helix and α1Thr67 in the E helix owing to the Thr67Ala substitution. In addition, deer mouse hemoglobin has a unique hydrogen bond at the α1β1 interface between residues α1Cys34 and β1Ser128.