Nucleotide sequence of nifH regions from Methanobacterium ivanovii and Methanosarcina barkeri 227 and characterization of glnB-like genes.

This brief note reports the nucleotide sequences of the second nifH region of Methanobacterium ivanovii and of the two nifH regions of Methanosarcina barkeri 227. In the three cases, nifH is followed by two ORF (open reading frames) similar to ORF105 and ORF128 respectively, which were previously found downstream of Methanococcus thermolithotrophicus nifH. These two ORF are followed by nifD in M. ivanovii as well as in the first nifH region of M. barkeri 227. Both types of ORF exhibit a strong homology with the glnB gene.