An in silico approach to study the interaction of phycobilisomes and chlorophyll in Anabaena cylindrica PCC7122

Cyanobacterial species are ubiquitous in nature and the pigments present are capable of trapping the energy from the sunlight for the process of photosynthesis. All cyanobacteria which photosynthesize contain a core green pigment chlorophyll a which are supported by the other ancillary pigments like the Phycobilisome/phycobilins. The combination of phycobilins and chlorophyll produces the characteristic blue green colour from which these organisms derive their name. Chlorophyll which portrays a vital function of absorbing light energy for photosynthesis. It is a porphyrin containing magnesium and exists in several forms which have different side chains. Phycocyanin and allophycocyanin are light harvesting accessory pigments to chlorophyll. To understand the role of these pigments homology modelling of phycocyanin and allophycocyanin with chlorophyll in Anabaena cylindrica PCC7122 was investigated in the present study. To study the interaction of chlorophyll in phycocyanin and allophycocyanin, docking analysis was performed. Two docking models each corresponding to phycocyanin and allophycocyanin with their energy minimization scores were obtained.Their interaction establishes the relationship between chlorophyll and the light harvesting components.