Difference between revisions of "Part:BBa K1998002"

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psbTB

Sequence and Features

Overview

This biobrick contains three genes from the photosystem II complex of Chlamydomonas reinhardtii - psbT abd psbB. It is driven by a Plac promoter at the beginning of the sequence, with RBS’s preceding each gene, and terminator sequence at the 3' end.

Parts composed in this operon:
psbT - antenna proteins CP47
psbB - photosystem II (PSII) chlorophyll-binding protein
These parts form operon 3 in our photosystem II pathway.

Biology & Literature

The second operon begins with psbT followed by psbB. Parts psbT and psbB make up the light harvesting complex inside the photosystem II complex [1]. They have a close interaction with the psbA and psbD complex helping to provide excitation energy from outer complexes onto them [2]. The psbT protein is a hydrophobic peptide that also has a single transmembrane helix which is associated with the PSII core complex [3] which binds to the complexes D1 and D2 heterodimer [4]. It's location in the core complex is believe to be at the PSII dimer interface [5]. Mutations in the psbT gene indicate that it's expression is not necessarily essential for the function of the PSII complex [4]. The role of psbT in repair of photo-damaged PSII complexes has also been discussed [3]. In addition the psbT gene maintains the stability of QA [5, 6].

The final gene of the composite part is psbB. The psbB protein is associated with the thylakoid membrane and forms part of the inner light harvesting complexes of PSII [7, 8].

Protein information

psbT
mass: 3.6kDa sequence: MEALVYTFLLVGTLGIIFFSIFFRDPPRMIK

psbB
mass: 56.1kDa sequence: MGLPWYRVHTVVINDPGRLISVHLMHTALVSGWAGSMALFEISVFDPSDPVLNPMWRQGMFVLPFMTRLGITQSWGGWTISGETATNPGIWSYEGVAAAHI ILSGALFLASVWHWTYWDLELFRDPRTGKTALDLPKIFGIHLFLSGLLCFGFGAFHVTGVFGPGIWVSDPYGLTGRVQPVAPSWGADGFDPYNPGGIASHHIAAGILGVLA GLFHLCVRPSIRLYFGLSMGSIETVLSSSIAAVFWAAFVVAGTMWYGSAATPIELFGPTRYQWDQGFFQQEIQKRVQASLAEGASLSDAWSRIPEKLAFYDYIGNNPAKGG LFRTGAMNSGDGIAVGWLGHASFKDQEGRELFVRRMPTFFETFPVLLLDKDGIVRADVPFRKAESKYSIEQVGVSVTFYGGELDGLTFTDPATVKKYARKAQLGEIFEFDR STLQSDGVFRSSPRGWFTFGHVCFALLFFFGHIWHGARTIFRDVFAGIDDDINDQVEFGKYKKLGDTSSLREAF

References

[1] Barber J. Photosystem two. Biochimica et Biophysica Acta (BBA)-Bioenergetics. 1998 Jun 10;1365(1):269-77.

[2] Luciński R, Jackowski G. The structure, functions and degradation of pigment-binding proteins of photosystem II. Acta Biochim Pol. 2006;53(4):693-708.

[3] Monod C, Takahashi Y, Goldschmidt-Clermont M, Rochaix JD. The chloroplast ycf8 open reading frame encodes a photosystem II polypeptide which maintains photosynthetic activity under adverse growth conditions. The EMBO journal. 1994 Jun 15;13(12):2747.

[4]Ohnishi N, Takahashi Y. PsbT polypeptide is required for efficient repair of photodamaged photosystem II reaction center. Journal of Biological Chemistry. 2001 Sep 7;276(36):33798-804.

[5] Ferreira KN, Iverson TM, Maghlaoui K, Barber J, Iwata S. Architecture of the photosynthetic oxygen-evolving center. Science. 2004 Mar 19;303(5665):1831-8.

[6] Ohnishi N, Kashino Y, Satoh K, Ozawa SI, Takahashi Y. Chloroplast-encoded polypeptide PsbT is involved in the repair of primary electron acceptor QA of photosystem II during photoinhibition in Chlamydomonas reinhardtii. Journal of Biological Chemistry. 2007 Mar 9;282(10):7107-15.

[7] Barber J, Nield J, Morris EP, Zheleva D, Hankamer B. The structure, function and dynamics of photosystem two. Physiologia plantarum. 1997 Aug 1;100(4):817-27.

[8] Bricker TM, Frankel LK. The structure and function of CP47 and CP43 in photosystem II. Photosynthesis research. 2002 May 1;72(2):131-46.