Ontology highlight
ABSTRACT: Background
Deer mice (Peromyscus maniculatus) that are native to high altitudes in the Rocky Mountains have evolved hemoglobins with an increased oxygen-binding affinity relative to those of lowland conspecifics. To elucidate the molecular mechanisms responsible for the evolved increase in hemoglobin-oxygen affinity, the crystal structure of the highland hemoglobin variant was solved and compared with the previously reported structure for the lowland variant.Results
Highland hemoglobin yielded at least two crystal types, in which the longest axes were 507 and 230 Å. Using the smaller unit cell crystal, the structure was solved at 2.2 Å resolution. The asymmetric unit contained two tetrameric hemoglobin molecules.Conclusions
The analyses revealed that ?Pro50 in the highland hemoglobin variant promoted a stable interaction between ?His45 and heme that was not seen in the ?His50 lowland variant. The ?Pro50 mutation also altered the nature of atomic contacts at the ?1?2/?2?1 intersubunit interfaces. These results demonstrate how affinity-altering changes in intersubunit interactions can be produced by mutations at structurally remote sites.
SUBMITTER: Inoguchi N
PROVIDER: S-EPMC5376325 | biostudies-literature | 2017
REPOSITORIES: biostudies-literature
Inoguchi Noriko N Mizuno Nobuhiro N Baba Seiki S Kumasaka Takashi T Natarajan Chandrasekhar C Storz Jay F JF Moriyama Hideaki H
PloS one 20170331 3
<h4>Background</h4>Deer mice (Peromyscus maniculatus) that are native to high altitudes in the Rocky Mountains have evolved hemoglobins with an increased oxygen-binding affinity relative to those of lowland conspecifics. To elucidate the molecular mechanisms responsible for the evolved increase in hemoglobin-oxygen affinity, the crystal structure of the highland hemoglobin variant was solved and compared with the previously reported structure for the lowland variant.<h4>Results</h4>Highland hemo ...[more]