TABLE 5.
Distribution of homologs of bacterioferritin, ferritin, and the iron sulfur storage protein IssA among 326 archaeal methanogen, methanotroph, and alkanotroph genomes
| Taxonomic order | Total no. of genomesa | No. of complete genomes/no. of draft genomes | No. of genomes with indicated protein homologsb |
||
|---|---|---|---|---|---|
| FtnA | Bfr | IssAc | |||
| Type I | |||||
| Methanobacteriales | 102 | 21/81 | 91 | 8 | 16 |
| Methanococcales | 20 | 15/5 | 13 | 0 | 14 |
| Methanopyrales | 3 | 3/0 | 0 | 0 | 3 |
| Type II | |||||
| Methanocellales | 4 | 3/1 | 1 | 4 | 0 |
| Methanomicrobiales | 32 | 11/21 | 16 | 0 | 24 |
| Methanosarcinales | 132 | 37/95 | 51 | 89 | 110 |
| Unclassified | |||||
| Archaeoglobales | 1 | 0/1 | 1 | 0 | 0 |
| Bathyarchaeota | 3 | 0/3 | 0 | 0 | 0 |
| Crenarchaeota | 4 | 0/4 | 0 | 4 | 0 |
| Hadesarchaeota | 2 | 0/2 | 0 | 0 | 1 |
| Methanomassiliicoccales | 12 | 4/8 | 0 | 3 | 6 |
| Methanonatronarchaeales | 1 | 0/1 | 0 | 0 | 0 |
| Verstraetearchaeota | 10 | 0/10 | 1 | 0 | 0 |
The number of genomes within a defined taxonomic group that encoded one or more homologs is indicated. Searched sequences (Data Set S2), the distribution of homologs and their accession numbers among the 326 individual genomes (Data Set S3), and information about the searched genomes (Data Set S1) are provided in the supplemental material.
FtnA, ferritin (nonheme dependent); Bfr, bacterioferritin (protoheme dependent); IssA, iron-sulfur storage protein.
The IssA homologs retrieved were further analyzed according to methods described by Vaccaro et al. (104) in order to assess their likely membership in IssA versus NifB and NafY families, as shown in Fig. S2.