ubiquitin family protein. similar to UBQ3 (POLYUBIQUITIN 3), protein binding [Arabidopsis thaliana] (TAIR:AT5G03240.3); similar to UBQ3 (POLYUBIQUITIN 3), protein binding [Arabidopsis thaliana] (TAIR:AT5G03240.2); similar to UBQ4 (ubiquitin 4), protein binding [Arabidopsis thaliana] (TAIR:AT5G20620.1); similar to ubiquitin [Mytilus edulis] (GB:CAJ32650.1); contains InterPro domain Ubiquitin; (InterPro:IPR000626)