Isolation of ribosomal particles is an essential step in the study of ribosomal components as
well as in the analysis of trans-acting factors that interact with the ribosome to regulate protein synthesis
and modulate the expression profile of the cell in response to different environmental conditions. In this
protocol, we describe a procedure for the isolation of 70S ribosomes from the unicellular cyanobacterium
Synechocystis sp. PCC 6803 (hereafter Synechocystis). We have successfully used this protocol in our
study of the cyanobacterial ribosomal-associated protein LrtA, which is a homologue of bacterial HPF
(hibernation promoting factor) (Galmozzi et al., 2016).España, Junta de Andalucía grant P07-CVI-02792 and group BIO-284España, MINECO y Fondo Social Europeo grant BFU2013-41712-
