Lysine as a heme iron ligand: A property common to three truncated hemoglobins from Chlamydomonas reinhardtii.

ABSTRACT:

Background

The nuclear genome of Chlamydomonas reinhardtii encodes a dozen hemoglobins of the truncated lineage. Four of these, named THB1-4, contain a single ~130-residue globin unit. THB1, which is cytoplasmic and capable of nitric oxide dioxygenation activity, uses a histidine and a lysine as axial ligands to the heme iron. In the present report, we compared THB2, THB3, and THB4 to THB1 to gain structural and functional insights into algal globins.

Methods

We inspected properties of the globin domains prepared by recombinant means through site-directed mutagenesis, electronic absorption, CD, and NMR spectroscopies, and X-ray crystallography.

Results

Recombinant THB3, which lacks the proximal histidine but has a distal histidine, binds heme weakly. NMR data demonstr

SUBMITTER: Johnson EA 

PROVIDER: S-EPMC6214630 | biostudies-literature | 2018 Dec

REPOSITORIES: biostudies-literature