Component of the PAF1 complex which is a multifunctional complex involved in transcription initiation via genetic interactions with TATA-binding proteins, elongation and transcription-coupled histone modification. Component of the PAF1 complex which consists of at least cdc-73, ctr-9, leo-1, pafo-1 and rtfo-1. Nuclear localization depends on pafo-1, leo-1 and ctr-9. RNAi mediated knock-down is embryonic lethal. Embryogenesis proceeds more slowly, with embryos displaying defects in the positioning and shape of epidermal cells. 60% of embryos arrest at the bean stage of embryogenesis without any significant change in body shape. Nuclear localization of rtf-1 is unaffected. Belongs to the CDC73 family.