5OOK
Structure of A. marina Phycocyanin contains overlapping isoforms
Summary for 5OOK
| Entry DOI | 10.2210/pdb5ook/pdb |
| Descriptor | Phycocyanin, alpha subunit, Phycocyanin, beta subunit, PHYCOCYANOBILIN, ... (5 entities in total) |
| Functional Keywords | models, phycobilisome, phycocyanin, a. marina, photosynthesis |
| Biological source | Acaryochloris marina More |
| Total number of polymer chains | 2 |
| Total formula weight | 38256.02 |
| Authors | Bar-Zvi, S.,Lahav, A.,Blankenship, E.R.,Adir, N. (deposition date: 2017-08-08, release date: 2018-06-20, Last modification date: 2024-01-17) |
| Primary citation | Bar-Zvi, S.,Lahav, A.,Harris, D.,Niedzwiedzki, D.M.,Blankenship, R.E.,Adir, N. Structural heterogeneity leads to functional homogeneity in A. marina phycocyanin. Biochim. Biophys. Acta, 1859:544-553, 2018 Cited by PubMed Abstract: The major light harvesting antenna in all cyanobacterial species is the phycobilisome (PBS). The smallest PBS identified to date is that of Acaryochloris marina (A. marina), composed of a single four-hexamer rod. We have determined the crystal structure of phycocyanin (AmPC), the major component of the A. marina PBS (AmPBS) to 2.1 Å. The basic unit of the AmPC is a heterodimer of two related subunits (α and β), and we show that the asymmetric unit contains a superposition of two α and two β isoforms, the products of the simultaneous expression of different genes. This is the first time to our knowledge that isolated proteins crystallized with such identifiable heterogeneity. We believe that the presence of the different isoforms allows the AmPBS to have a significant bathochromic shift in its fluorescence emission spectrum, allowing, in the total absence of allophycocyanin, a better overlap with absorption of the chlorophyll d-containing reaction centers. We show that this bathochromic shift exists in intact AmPBS as well as in its disassembled components, thus suggesting that AmPC can efficiently serve as the AmPBS terminal emitter. PubMed: 29704497DOI: 10.1016/j.bbabio.2018.04.007 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.1 Å) |
Structure validation
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