Part of the cellular protein quality control system with a specific role in salt stress response. May facilitate protein homeostasis, together with chemical chaperones that accumulate during the salt stress response. Increased levels of YocM protects against both heat and salt stress. In vitro, displays an unusual aggregase chaperone activity. Forms homodimers, homotetramers and higher oligomers. Localizes to stress-induced intracellular protein aggregates. Induced upon salt stress conditions. Deletion of the gene increases sensitivity toward salt stress. Belongs to the small heat shock protein (HSP20) family.