Part:BBa_K1998008
psbELJ-TB
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21INCOMPATIBLE WITH RFC[21]Illegal BglII site found at 1286
- 23COMPATIBLE WITH RFC[23]
- 25INCOMPATIBLE WITH RFC[25]Illegal AgeI site found at 67
Illegal AgeI site found at 173
Illegal AgeI site found at 457
Illegal AgeI site found at 466 - 1000COMPATIBLE WITH RFC[1000]
Overview
This composite part is composed of operons psbELJ and psbTB found in the photosystem II pathway of Chlamydomonas reinhardtii. Three subunits make up the psbELJ cluster and are involved in the structure of the thylkaoid membrane complexes. The psbT and psbB protein function is not well known however it appears to be involved in the dimerization of Photosystem II and is essential for photosynthetic activity.
The first operon encoded in this part contains psbE, psbL, and psbJ, driven by Plac promoter, with RBS preceeding each gene, and terminator at the 3' end. The second operon is composed of the psbT and psbB genes which both have a RBS preceding them.
This part contains two operons that make up our Photosystem II Pathway.
Biology & Literature
The first operon in this composite part is composed of psbE, psbL and psbJ. The first gene, psbE encodes the α subunits of a transmembrane component of the photosystem II complex [1, 2]. It has also been shown to be closely liked to the psbF gene [3]. Whilst transcription of the psbE gene has been shown to be independent of any other genes, it has been shown that it can be co-transcribed with the psbL and psbJ genes which are located further downstream [4, 5].
The psbL gene is a 4.5kDA protein which makes up a component of the photosystem II reaction centre. It contains an alpha helical domain which spans the membrane (Anbudurai, Pakrasi 1993) which has an important function in supporting the primary quinone acceptor present at the reaction centre core complex (Kitamura, K., et al., 1994). In addition the protein’s carboxyl terminal end is responsible in recovering the electron transfer activity in the complex (Ozawa, S., et al., 1997).
The third gene in this part, psbJ contains a single transmembrane helix (Nowaczyk, M. M., et al., 2012). With a molecular weight of 41.kDa, the protein that the gene encodes has a role in the regulation of photosystem II complexes within the thylakoid membrane (Lind, L. K., et al., 1993). It has been indicated that the studies of mutants have shown that organisms without the psbJ gene produce lower electron transfer efficiency in the photosystem II complex (Regel, R. E., et al., 2001).
The second operon begins with psbT followed by psbB. Parts psbT and psbB make up the light harvesting complex inside the photosystem II complex (Barber et al. 1997). It has a close interaction with the psbA and psbD complex helping to provide excitation energy from outer complexes onto them (Lucinski and Jackowski 2006).
Protein information
psbE mass: 9.3kDa sequence: MAGKPVERPFSDILTSIRYWVIHSITVPALFIAGWLFVSTGLAYDVFGTPRPNEYFTEDRQEAPLITDRFNALEQVKKLSGN
psbL mass: 4.43kDa sequence: MARPNPNKQVVELNRTSLYWGLLLIFVLAVLFSSYIFN
psbJ mass: 4.29kDa sequence: MSNTGTTGRIPLWLVGTVVGTLAIGLLAVFFYGSYVGLGSSL
psbT mass: sequence:
psbB
mass:
sequence:
References
[1] Cramer WA, Tae GS, Furbacher PN, Böttger M. The enigmatic cytochrome b‐559 of oxygenic photosynthesis. Physiologia Plantarum. 1993 Aug 1;88(4):705-11.
[2] Tae GS, Black MT, Cramer WA, Vallon O, Bogorad L. Thylakoid membrane protein topography: transmembrane orientation of the chloroplast cytochrome b-559 psbE gene product. Biochemistry. 1988 Dec;27(26):9075-80.
[3] Erickson JM, Rochaix JD. The photosystems: Structure, function, and molecular biology. Topics in Photosynthesis. 1992;11:101-78.
[5] Kiss É, Kós PB, Chen M, Vass I. A unique regulation of the expression of the psbA, psbD, and psbE genes, encoding the D1, D2 and cytochrome b559 subunits of the Photosystem II complex in the chlorophyll d containing cyanobacterium Acaryochloris marina. Biochimica et Biophysica Acta (BBA)-Bioenergetics. 2012 Jul 31;1817(7):1083-94.
| None |