Rubredoxin A (RubA) is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

conserved across all studied oxygenic photoautotrophs.

Structure

As of March 2015 there was no

crystal structure In crystallography, crystal structure is a description of ordered arrangement of atoms, ions, or molecules in a crystalline material. Ordered structures occur from intrinsic nature of constituent particles to form symmetric patterns that repeat ...

of RubA although a structure of the homologous protein from a cryptomonad was determined using

NMR Nuclear magnetic resonance (NMR) is a physical phenomenon in which atomic nucleus, nuclei in a strong constant magnetic field are disturbed by a weak oscillating magnetic field (in the near and far field, near field) and respond by producing ...

. Investigation of the

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

however indicates that it differs from other known rubredoxins in being bound to the

thylakoid Thylakoids are membrane-bound compartments inside chloroplasts and cyanobacterium, cyanobacteria. They are the site of the light-dependent reactions of photosynthesis. Thylakoids consist of a #Membrane, thylakoid membrane surrounding a #Lumen, ...

membrane via a

C-terminal The C-terminus (also known as the carboxyl-terminus, carboxy-terminus, C-terminal tail, carboxy tail, C-terminal end, or COOH-terminus) is the end of an amino acid chain (protein or polypeptide), terminated by a free carboxyl group (-COOH). When t ...

transmembrane helix.

Function

An investigation of '' Guillardia theta'' noted that RubA had a similar distribution to

Photosystem II Photosystem II (or water-plastoquinone oxidoreductase) is the first protein complex in the light-dependent reactions of oxygenic photosynthesis. It is located in the thylakoid membrane of plants, algae, and cyanobacteria. Within the photosystem ...

(PSII) and immunological experiments indicated the presence of RubA in PSII complexes isolated from ''

Spinacia oleracea Spinach (''Spinacia oleracea'') is a leafy green flowering plant native to Central Asia, Central and Western Asia. It is of the order Caryophyllales, family Amaranthaceae, subfamily Chenopodioideae. Its leaves are a common vegetable consumed eit ...

''. 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, while the same mutation within '' Chlamydomonas reinhardtii'' and in ''

Arabidopsis thaliana ''Arabidopsis thaliana'', the thale cress, mouse-ear cress or arabidopsis, is a small plant from the mustard family (Brassicaceae), native to Eurasia and Africa. Commonly found along the shoulders of roads and in disturbed land, it is generally ...

'' results in a total absence of PSII. 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 Photosystem I (PSI, or plastocyanin–ferredoxin oxidoreductase) is one of two photosystems in the Light-dependent reactions, photosynthetic light reactions of algae, plants, and cyanobacteria. Photosystem I is an integral membrane ...

(PSI), rather than affecting PSII.

References

{{Reflist Bacterial proteins Iron–sulfur proteins