Details

Autor(en) / Beteiligte

• Melnicki, Matthew R.
• Leverenz, Ryan L.
• Sutter, Markus
• López-Igual, Rocío
• Wilson, Adjélé
• Pawlowski, Emily G.
• Perreau, François
• Kirilovsky, Diana
• Kerfeld, Cheryl A.

Titel

Structure, Diversity, and Evolution of a New Family of Soluble Carotenoid-Binding Proteins in Cyanobacteria

Ist Teil von

• Molecular plant, 2016-10, Vol.9 (10), p.1379-1394

Ort / Verlag

England: Elsevier Inc

Erscheinungsjahr

2016

Quelle

MEDLINE

Beschreibungen/Notizen

• Using a phylogenomic approach, we have identified and subciassified a new family of carotenoid-binding proteins. These proteins have sequence homology to the N-terminal domain （NTD） of the Orange Carotenoid Protein （OCP）, and are referred to as Helical Carotenoid Proteins （HCPs）. These proteins comprise at least nine distinct ciades and are found in diverse organisms, frequently as multiple paralogs representing the distinct ciades. These seem to be out-paralogs maintained from ancient duplications associated with subfunctionalization. All of the HCPs share conservation of the residues for carotenoid binding, and we confirm that carotenoid binding is a fundamental property of HCPso We solved two crystal structures of the Nostoc sp. PCC 7120 HCP1 protein, each binding a different carotenoid, suggesting that the proteins flexibly bind a range of carotenoids. Based on a comprehensive phylogenetic analysis, we propose that one of the HCP subtypes is likely the evolutionary ancestor of the NTD of the OCP, which arose following a domain fusion evenS. However, we predict that the majority of HCPs have functions distinct from the NTD of the OCP. Our results demonstrate that the HCPs are a new family of functionally diverse carotenoid-binding proteins found among ecophysiologically diverse cyanobacteria.