Difference between revisions of "Part:BBa K1640020"

Latest revision as of 01:39, 19 September 2015

psbA

Sequence and Features

Overview

This biobrick contains one gene from the photosystem II complex of Chlamydomonas reinhardtii - psbA.

- psbA encodes D1, a subunit of the Photosystem II reaction centre.

This part was designed in conjunction with BBa_K1640024, and together they form operon 1 in our set of photosystem II operons:

Biology & Literature

PsbA encodes the Photosystem II reaction centre subunit D1. This product forms a heterodimer with D2, encoded by psbD, to form the Photosystem II reaction centre (Marder, Chapman, Telfer, Nixon, & Barber, 1987). The primary function of the D1/D2 reaction centre complex is to transfer electrons from the chlorophyll P680 to two quinones, designated QA and QB. To this end, D1 has functions both at the oxidation and reduction stages of the reaction.

D1 accepts electrons from P680, transferring it to QB. A tyrosine of D1 reduces the resulting P680 cation, resulting in a tyrosine radical. This radical acts as an oxidising agent for the oxidation of water through the oxygen evolving complex (OEC) of PSII (Ferreira, Iverson, Maghlaoui, Barber, & Iwata, 2004). In addition, this protein is vital to the assembly of both the OEC and QB within PSII. Site-directed mutagenesis studies have revealed an aspartate residue of D1 to be both structurally coupled to and involved in the assembly of the Mn cluster within the OEC (Chu, Debus, & Babcock, 2001; Nixon & Diner, 1992). Similarly, inhibition studies involving the binding of herbicides to D1 have revealed this protein to contain a niche for the binding of QB (Erickson et al., 1989; Jansen, Mattoo, Malkin, & Edelman, 1993).

Protein information

psbA

mass: 50.92kDa

sequence:
METLFNGTLTVGGRDQETTGFAWWSGNARLINLSGKLLGAHVAHAGLIVFWAGAMNLFEVSHFVPEKPMYEQ GLILLPHIATLGYGVGPGGEIIDTFPYFVSGVLHLISSAVLGFGGVYHSLIGPETLEESYPFFGYVWKDKNK MTNILGYHLIMLGLGAWLLVWKAMYFGGVYDTWAPGGGDVRVITNPTTNAAVIFGYLVKSPFGGDGWICSVD NMEDIIGGHIWIGTLEILGGIWHIYTTPWPWARRAFVWSGEAYLSYSLGAIGVMGFIACCMSWFNNTAYPSE FYGPTGPEASQSQAFTFLVRDQRLGANVASAQGPTGLGKYLMRSPTGEIIFGGETMRFWDFRGPWLEPLRGP NGLDLNKLKNDIQPWQERRAAEYMTHAPLGSLNSVGGVATEINAVNFVSPRSWLACSHFCLGFFFFIGHLWH AGRARAAAAGFEKGIDRFDEPVLSMRPLD*

Part verification

Visualisation of psbA showing expected banding is shown in the following gel image, top row second set of lanes, with left lane part showing EcoRI digest, right lane showing EcoRI + PstI double digest. This part has been sequenced to confirm design with final biobrick.

References

Chu, H.-A., Debus, R. J., & Babcock, G. T. (2001). D1-Asp170 Is Structurally Coupled to the Oxygen Evolving Complex in Photosystem II As Revealed by Light-Induced Fourier Transform Infrared Difference Spectroscopy†. Biochemistry, 40(7), 2312-2316. doi:10.1021/bi0022994

Erickson, J. M., Pfister, K., Rahire, M., Togasaki, R. K., Mets, L., & Rochaix, J. D. (1989). Molecular and biophysical analysis of herbicide-resistant mutants of Chlamydomonas reinhardtii: structure-function relationship of the photosystem II D1 polypeptide. The Plant Cell, 1(3), 361-371.

Ferreira, K. N., Iverson, T. M., Maghlaoui, K., Barber, J., & Iwata, S. (2004). Architecture of the photosynthetic oxygen-evolving center. Science, 303(5665), 1831-1838.

Jansen, M. A. K., Mattoo, A. K., Malkin, S., & Edelman, M. (1993). Direct Demonstration of Binding-Site Competition between Photosystem II Inhibitors at the QB Niche of the D1 Protein. Pesticide Biochemistry and Physiology, 46(1), 78-83. doi:http://dx.doi.org/10.1006/pest.1993.1039

Marder, J., Chapman, D., Telfer, A., Nixon, P., & Barber, J. (1987). Identification of psbA and psbD gene products, D1 and D2, as reaction centre proteins of photosystem 2. Plant molecular biology, 9(4), 325-333.

Nixon, P. J., & Diner, B. A. (1992). Aspartate 170 of the photosystem II reaction center polypeptide D1 is involved in the assembly of the oxygen-evolving manganese cluster. Biochemistry, 31(3), 942-948. doi:10.1021/bi00118a041