Significantly enhanced heme retention ability of myoglobin engineered to mimic the third covalent linkage by nonaxial histidine to heme (vinyl) in synechocystis hemoglobin.

ABSTRACT: Heme proteins, which reversibly bind oxygen and display a particular fold originally identified in myoglobin (Mb), characterize the "hemoglobin (Hb) superfamily." The long known and widely investigated Hb superfamily, however, has been enriched by the discovery and investigation of new classes and members. Truncated Hbs typify such novel classes and exhibit a distinct two-on-two α-helical fold. The truncated Hb from the freshwater cyanobacterium Synechocystis exhibits hexacoordinate heme chemistry and bears an unusual covalent bond between the nonaxial His(117) and a heme porphyrin 2-vinyl atom, which remains tightly associated with the globin unlike any other. It seems to be the most stable Hb known to date, and His(117) is the dominant force holding the heme. Mutations of amino acid resi

SUBMITTER: Uppal S 

PROVIDER: S-EPMC4303654 | biostudies-literature | 2015 Jan

REPOSITORIES: biostudies-literature