NOL1/NOP2/Sun domain family member 4 putative methyltransferase NSUN4 NOP2/Sun RNA methyltransferase family member 4 5-methylcytosine tRNA methyltransferase NSUN4 sperm head and tail associated protein 5-methylcytosine rRNA methyltransferase NSUN4 NOP2/Sun domain family, member 4 SHTAP