Binding of pigments to the cyanobacterial high-light-inducible protein HliC

0491694 - MBÚ 2019 RIV NL eng J - Journal Article
Shukla, Mahendra K. - Llansola-Portoles, M.J. - Tichý, Martin - Pascal, A.A. - Robert, B. - Sobotka, Roman
Binding of pigments to the cyanobacterial high-light-inducible protein HliC.
Photosynthesis Research. Roč. 137, č. 1 (2018), s. 29-39. ISSN 0166-8595. E-ISSN 1573-5079
R&D Projects: GA MŠMT(CZ) LO1416; GA MŠMT(CZ) ED2.1.00/19.0392; GA ČR(CZ) GA17-08755S
Institutional support: RVO:61388971
Keywords : Synechocystis * HLIPs * Raman spectroscopy
OECD category: Microbiology
Impact factor: 3.057, year: 2018

Cyanobacteria possess a family of one-helix high-light-inducible proteins (HLIPs) that are widely viewed as ancestors of the light-harvesting antenna of plants and algae. HLIPs are essential for viability under various stress conditions, although their exact role is not fully understood. The unicellular cyanobacterium Synechocystis sp. PCC 6803 contains four HLIPs named HliA-D, and HliD has recently been isolated in a small protein complex and shown to bind chlorophyll and beta-carotene. However, no HLIP has been isolated and characterized in a pure form up to now. We have developed a protocol to purify large quantities of His-tagged HliC from an engineered Synechocystis strain. Purified His-HliC is a pigmented homo-oligomer and is associated with chlorophyll and beta-carotene with a 2:1 ratio. This differs from the 3:1 ratio reported for HliD. Comparison of these two HLIPs by resonance Raman spectroscopy revealed a similar conformation for their bound beta-carotenes, but clear differences in their chlorophylls. We present and discuss a structural model of HliC, in which a dimeric protein binds four chlorophyll molecules and two beta-carotenes.
Permanent Link: http://hdl.handle.net/11104/0285380