# Strong interaction of CpcL with photosystem I cores induced in heterocysts of Anabaena sp. PCC 7120

## TL;DR

This paper investigates how a protein called CpcL interacts with photosystem I in a type of cyanobacteria called Anabaena sp. PCC 7120.

## Contribution

The study identifies CpcL as a component of phycobilisomes bound to photosystem I in heterocysts of Anabaena sp. PCC 7120.

## Key findings

- CpcL was identified in photosystem I fractions using mass spectrometry.
- The organization of PSI-phycobilisome supercomplexes varies in Anabaena sp. PCC 7120.
- CpcL binding to PSI may be influenced by environmental conditions.

## Abstract

Phycobilisomes (PBSs) are photosynthetic light-harvesting antennae and appear to be loosely bound to photosystem I (PSI). We previously found unique protein bands in each PSI fraction in heterocysts of
Anabaena
sp. PCC 7120 by two-dimensional blue native/SDS-PAGE; however, the protein bands have not been identified. Here we analyzed the protein bands by mass spectrometry, which were identified as CpcL, one of the components in PBSs. As different composition and organization
of
Anabaena
PSI-PBS supercomplexes were observed, the expression and binding properties of PBSs including CpcL to PSIs in this cyanobacterium may be diversified in response to its living environments.