La antigen binds to the oligo(U) 3' termini of nascent RNA polymerase III transcripts and facilitates transcriptional termination and reinitiation by this enzyme13,-17. It has also been reported to function as an ATP-dependent helicase able to melt RNA-DNA hybrids. Description: Calf Thymus. Alternative Names: SSB protein, Single stranded binding protein, Single stranded binding La protein