Rubredoxin A

Rubredoxin A (RubA) is a protein conserved across all studied oxygenic photoautotrophs.[1]

Structure

As of March 2015 there was no crystal structure of RubA although a structure of the homologous protein from a cryptomonad was determined using NMR.[2] Investigation of the gene however indicates that it differs from other known rubredoxins in being bound to the thylakoid membrane via a C-terminal transmembrane helix.[1][3][4]

Function

An investigation of Guillardia theta noted that RubA had a similar distribution to Photosystem II (PSII) and immunological experiments indicated the presence of RubA in PSII complexes isolated from Spinacia oleracea.[3] In Synechocystis sp. PCC 6803 it has been demonstrated that the insertion of an antibiotic cassette into the rubA gene results in a marked decrease in the amount of PSII present,[1] while the same mutation within Chlamydomonas reinhardtii and in Arabidopsis thaliana results in a total absence of PSII.[1]

Conversely, another study performed in Synechococcus sp. PCC 7002 indicated that mutation of the rubA gene interfered with iron-sulphur cluster assembly in Photosystem I (PSI), rather than affecting PSII.[4][5]

References

1. Calderon, R. H., García-Cerdán, J. G., Malnoë, A., Cook, R., Russell, J. J., Gaw, C., Dent, R. M., de Vitry, C. and Niyogi, K. K. (July 2013). "A Conserved Rubredoxin Is Necessary for Photosystem II Accumulation in Diverse Oxygenic Photoautotrophs". The Journal of Biological Chemistry. 288 (37): 26688–26696. doi:10.1074/jbc.M113.487629. PMC 3772215. PMID 23900844.
2. Schweimer, K., Hoffmann, S., Wastl, J., Maier, U.G., Rösch, P., and Sticht H. (2000). "Solution structure of a zinc substituted eukaryotic rubredoxin from the cryptomonad alga "Guillardia theta"". Protein Science. 9 (8): 1474–1486. doi:10.1110/ps.9.8.1474. PMC 2144721. PMID 10975569.
3. Wastl, J., Duin, E. C., Iuzzolino, L., Dörner, W., Link. T., Dau, H., Lingelbach, K. and Maier U. G. (2000). "Eukaryotically Encoded and Chloroplast-located Rubredoxin Is Associated with Photosystem II". The Journal of Biological Chemistry. 275 (39): 30058–30068. doi:10.1074/jbc.M004629200. PMID 10878021.
4. Shen, G., Zhao, J., Reimer, S. K., Antonkine, M. L., Cai, Q., Weiland, S. M., Golbeck, J. H. and Bryant, D. A. (2002). "Assembly of Photosystem II: I. Inactivation of The rubA Gene Encoding A Membrane-Associated Rubredoxin In The Cyanobacterium Synechococcus sp. PCC 7002 Causes A Loss of Photosystem I Activity". The Journal of Biological Chemistry. 277 (23): 20343–20354. doi:10.1074/jbc.M201103200. PMID 11914373.
5. Shen, G., Antonkine, M. L., van der Est, A., Vassiliev, I. R., Brettel, K., Bittl, R., Zech, S. G., Zhao, J., Stehlik, D., Bryant, D. A. and Golbeck, J. H. (2002). "Assembly of Photosystem I: II. Rubredoxin Is Required for the Assembly of Fx in Synechococcus sp. PCC 7002 As Shown by Optical and EPR Spectroscopy". The Journal of Biological Chemistry. 277 (23): 20355–20366. doi:10.1074/jbc.M201104200. PMID 11914374.