This domain is found in a group of putative heme-iron utilisation proteins, such as HugZ. It can also be found in C-terminal of the glutamyl-tRNA reductase-binding (GluTRBP) protein from Arabidopsis [1]. 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 [2]. GluTRBP is necessary for efficient photosynthetic electron transport in chloroplasts [3].

1: Crystal structure of Arabidopsis glutamyl-tRNA reductase in complex with its stimulator protein. Zhao A, Fang Y, Chen X, Zhao S, Dong W, Lin Y, Gong W, Liu L; Proc Natl Acad Sci U S A. 2014;111:6630-6635. PMID:24753615

2: An Arabidopsis GluTR binding protein mediates spatial separation of 5-aminolevulinic acid synthesis in chloroplasts. Czarnecki O, Hedtke B, Melzer M, Rothbart M, Richter A, Schroter Y, Pfannschmidt T, Grimm B; Plant Cell. 2011;23:4476-4491. PMID:22180625

3: Arabidopsis thaliana PGR7 encodes a conserved chloroplast protein that is necessary for efficient photosynthetic electron transport. Jung HS, Okegawa Y, Shih PM, Kellogg E, Abdel-Ghany SE, Pilon M, Sjolander K, Shikanai T, Niyogi KK; PLoS One. 2010;5:e11688. PMID:20657737