InterPro domain: IPR037119

This entry represents a domain superfamily that can be found in a group of putative haem-iron utilisation proteins, such as HugZ, a class of heme oxygenase that belongs to the PPOX family and lacks homology to the HmuO family. This enzyme releases iron during the conversion of heme to biliverdin [ 1 , 2 ].

This domain can also be found at the C terminus of the glutamyl-tRNA reductase-binding (GluTRBP) protein from Arabidopsis [ 3 ]. GluTRBP is involved in the regulation of glutamyl-tRNA reductase (GluTR) which is important for the synthesis and distribution of 5-aminolevulinate, a precursor in heme and chlorophyll biosynthesis [ 4 ]. GluTRBP is necessary for efficient photosynthetic electron transport in chloroplasts [ 5 , 6 ].

1. Crystal structure of Campylobacter jejuni ChuZ: A split-barrel family heme oxygenase with a novel heme-binding mode. Biochem. Biophys. Res. Commun. 415, 82-7
2. Crystal structure of HugZ, a novel heme oxygenase from Helicobacter pylori. J. Biol. Chem. 286, 1537-44
3. Crystal structure of Arabidopsis glutamyl-tRNA reductase in complex with its stimulator protein. Proc. Natl. Acad. Sci. U.S.A. 111, 6630-5
4. An Arabidopsis GluTR binding protein mediates spatial separation of 5-aminolevulinic acid synthesis in chloroplasts. Plant Cell 23, 4476-91
5. Arabidopsis thaliana PGR7 encodes a conserved chloroplast protein that is necessary for efficient photosynthetic electron transport. PLoS ONE 5, e11688