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Publication Abstract from PubMed

Phycoerythrin (PE) is green light-absorbing pigment-protein that assists in efficient light harvesting in cyanobacteria and red-algae. PE in cyanobacteria stays less studied so far as compared to that in red algae. In this study, PE from marine cyanobacteria Halomicronema sp. R31DM is purified and subjected for its structural characterisation by X-ray crystallography in order to understand its light-harvesting characteristics. The crystal structure is solved to a resolution-limit of 2.21 A with reasonable R-factors values, 0.16/0.21 (R(work)/ R(free)). PE forms hexamer of hetero-dimers made up of two peptide chains, alpha- and beta-subunits containing 2 and 3 phycoerythrobilin (PEB) chromophores covalently attached to them, respectively. Geometry of five chromophores is analysed along with their relative position within the PE hexamer. Also, their interactions with the surrounding microenvironment are analysed. The plausible energy transfer pathways in hexamer structure have been predicted based on relative position and geometry of chromophores. This structure enriches the structural information of cyanobacterial PE in order to understand its light-harvesting capacity.Communicated by Ramaswamy H. Sarma.

Crystal structure analysis of phycoerythrin from marine cyanobacterium Halomicronema.,Patel SN, Sonani RR, Gupta GD, Singh NK, Kumar V, Madamwar D J Biomol Struct Dyn. 2023 Jun;41(9):3752-3761. doi: , 10.1080/07391102.2022.2055647. Epub 2022 Mar 31. PMID:35354393^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.