Comment | Members of this radical SAM protein subfamily, designated NirJ1, occur in genomic contexts with a paralog NirJ2 and with other nitrite reductase operon genes associated with heme d1 biosynthesis, as in Heliobacillus mobilis and Heliophilum fasciatum. NirJ1 is presumed by bioinformatics analysis (Xiong, et al.) to be a heme d1 biosynthesis protein by context, perhaps involved in conversions of acetate groups to methyl groups in conversion from uroporphyrinogen III. A very closely related protein, involved in alternative heme b biosynthesis, occurs in Desulfovibrio and in methanogens. |