InterPro domain: IPR017506

Members of this protein family are about 265 residues long and each contains an S4 RNA-binding domain of about 48 residues. The member from the Cyanobacterium, Synechocystis sp. (strain PCC 6803), was detected as a novel polypeptide in a highly purified preparation of active photosystem II [ 1 ]. The phylogenetic distribution, including Cyanobacteria and Arabidopsis, supports a role in photosystem II, although the high bit score cut-off for this model excludes similar sequences in non-photosynthetic organisms such as Carboxydothermus hydrogenoformans, a Gram-positive bacterium.

1. Low-molecular-mass polypeptide components of a photosystem II preparation from the thermophilic cyanobacterium Thermosynechococcus vulcanus. Plant Cell Physiol. 43, 1366-73