NOP2/Sun domain family, member 5 pseudogene 1, or NOP2/Sun RNA methyltransferase family member 5 pseudogene 1, is a human gene encoded by NSUN5P1. It may also be known as: Putative NOL1/NOP2/Sun domain family member 5B; Williams-Beuren syndrome chromosomal region 20B protein; Putative NOL1/NOP2/Sun domain family member 5B ; Williams Beuren syndrome chromosome region 20B; NSUN5B; WBSCR20B. The encoded protein is an enzyme with an amino acid length of 163 and a mass of 17.7 kDa. Other isoforms may exist. NOP2/Sun domain family, member 5 pseudogene 1 is a member of the Class I-like SAM-binding methyltransferase superfamily, RsmB/NOP family.