Subunit of the tRNA splicing endonuclease%3B tRNA splicing endonuclease (Sen complex) is composed of Sen2p%2C Sen15p%2C Sen34p%2C and Sen54p%3B Sen complex also cleaves the CBP1 mRNA at the mitochondrial surface%3B Sen2p contains the active site for tRNA 5' splice site cleavage and has similarity to Sen34p and to Archaeal tRNA splicing endonuclease%3B