| [B] Acaryochloris marina (strain MBIC 11017) | ACAM101968 | B0BYV8 | RNA polymerase sigma-70 factor |
| [B] Cyanothece (strain ATCC 51142) | CYAA501853 | B1X0D4 | Group 2 sigma-70 RNA polymerase sigma factor C |
| [B] Cyanothece sp. (strain PCC 7425 / ATCC 29141) | CYAP401537 | B8HRG7 | RNA polymerase sigma factor |
| [B] Microcystis aeruginosa (strain NIES-843) | MICAN00859 | B0JRK7 | Group 2 RNA polymerase sigma factor |
| [B] Synechococcus sp. (strain ATCC 27264 / PCC 7002 / PR-6) | SYNP200262 | B1XMU3 | Group 2 sigma factor |
| [B] Synechococcus sp. (strain CC9311) | SYNS302792 | Q0I680 | RNA polymerase sigma-70 factor family protein |
| [B] Synechococcus sp. (strain CC9605) | SYNSC02535 | Q3AGF8 | possible type II alternative RNA polymerase sigma factor |
| [B] Synechococcus sp. (strain CC9902) | SYNS902214 | Q3AVS8 | possible type II alternative RNA polymerase sigma factor |
| [B] Synechococcus sp. (strain JA-2-3B'a(2-13)) | SYNJB02616 | Q2JIA4 | RNA polymerase sigma-70 factor family identified by match to protein family HMM PF00140; match to protein family HMM PF04539; match to protein family HMM PF04542; match to protein family HMM PF04545 |
| [B] Synechococcus sp. (strain JA-3-3Ab) | SYNJA01896 | Q2JT33 | RNA polymerase sigma-70 factor family identified by match to protein family HMM PF00140; match to protein family HMM PF04539; match to protein family HMM PF04542; match to protein family HMM PF04545 |
| [B] Synechococcus sp. (strain PCC 6301) | SYNP602240 | Q5MZT5 | sigC group2 RNA polymerase sigma factor RpoD5 |
| [B] Synechococcus sp. (strain RCC307) | SYNR302436 | A5GWT3 | Alternative RNA polymerase sigma factor, sigma-70 family |
| [B] Synechococcus sp. (strain WH7803) | SYNPW02456 | A5GPM0 | Alternative RNA polymerase sigma factor, sigma-70 family |
| [B] Synechococcus sp. (strain WH8102) | SYNPX02424 | Q7U3K5 | RNA polymerase sigma factor |
| [B] Synechocystis sp. (strain PCC 6803) | SYNY302420 | RPSC_SYNY3 | Probable RNA polymerase sigma-C factor |
| [B] Anabaena variabilis (strain ATCC 29413 / PCC 7937) | ANAVT01150 | Q3MDZ8 | Sigma 28 (Flagella/Sporulation) |
| [B] Anabaena sp. (strain PCC 7120) | ANASP01675 | RPSC_ANASP | RNA polymerase sigma-C factor |
| [B] Nostoc punctiforme (strain ATCC 29133 / PCC 73102) | NOSP700908 | B2IV51 | RNA polymerase, sigma 70 subunit, RpoD family |
| [B] Trichodesmium erythraeum (strain IMS101) | TRIEI01629 | Q113W5 | RNA polymerase, sigma 28 subunit |
| [B] Prochlorococcus marinus (strain MIT 9303) | PROM302916 | A2CDX6 | Putative type II alternative RNA polymerase sigma factor |
| [B] Prochlorococcus marinus (strain MIT 9313) | PROMM02207 | Q7V3X0 | Putative type II alternative RNA polymerase sigma factor |