Par17, a member of the

parvulin ] Parvulin, a 92-amino acid protein discovered in E. coli in 1994,Rahfeld JU, Schierhorn A, Mann KH. (1994). A novel peptidyl-prolyl cis/trans isomerase from Escherichia coli. ''FEBS Lett'' 343:65. is the smallest known protein with prolyl isomeras ...

family of peptidyl-prolyl-cis/trans-isomerases (PPIases), is an isoform of parvulin 14 (Par14) and originates from alternative transcription initiation of the PIN4 gene on chromosome Xq13 in humans. Par17, which carries a 25 residue N-terminal extension, shares the complete successive amino acid sequence with Par14. In contrast to Par14, Par17 is exclusively expressed in

Hominidae The Hominidae (), whose members are known as the great apes or hominids (), are a taxonomic Family (biology), family of primates that includes eight Neontology#Extant taxa versus extinct taxa, extant species in four Genus, genera: ''Orangutan ...

, as

ORF ORF or Orf may refer to: * Norfolk International Airport, IATA airport code ORF * Observer Research Foundation, an Indian research institute * One Race Films, a film production company founded by Vin Diesel * Open reading frame, a portion of the g ...

s were only found within the genomes of

orangutan Orangutans are great apes native to the rainforests of Indonesia and Malaysia. They are now found only in parts of Borneo and Sumatra, but during the Pleistocene they ranged throughout Southeast Asia and South China. Classified in the genus ...

gorilla Gorillas are primarily herbivorous, terrestrial great apes that inhabit the tropical forests of equatorial Africa. The genus ''Gorilla'' is divided into two species: the eastern gorilla and the western gorilla, and either four or five su ...

chimpanzee The chimpanzee (; ''Pan troglodytes''), also simply known as the chimp, is a species of Hominidae, great ape native to the forests and savannahs of tropical Africa. It has four confirmed subspecies and a fifth proposed one. When its close rel ...

s and

human Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, great apes characterized by their Prehistory of nakedness and clothing ...

s. The N-terminal extension seems to be responsible for the translocation of Par17 to the mitochondrial matrix. Par17 is involved in

tubulin Tubulin in molecular biology can refer either to the tubulin protein superfamily of globular proteins, or one of the member proteins of that superfamily. α- and β-tubulins polymerize into microtubules, a major component of the eukaryotic cytosk ...

and

actin Actin is a family of globular multi-functional proteins that form microfilaments in the cytoskeleton, and the thin filaments in muscle fibrils. It is found in essentially all eukaryotic cells, where it may be present at a concentration of ...

polymerization as well as in

hepatitis B virus Hepatitis B virus (HBV) is a partially double-stranded DNA virus, a species of the genus '' Orthohepadnavirus'' and a member of the '' Hepadnaviridae'' family of viruses. This virus causes the disease hepatitis B. Classification Hepatitis B ...

replication.{{cite journal , doi = 10.1128/JVI.01840-18 , title = Parvulin 14 and Parvulin 17 Bind to HBX and cccDNA and Upregulate Hepatitis B Virus Replication from cccDNA to Virion in an HBX-Dependent Manner , year = 2018 , last1 = Saeed , first1 = Umar , last2 = Kim , first2 = Jumi , last3 = Piracha , first3 = Zahra Zahid , last4 = Kwon , first4 = Hyeonjoong , last5 = Jung , first5 = Jaesung , last6 = Chwae , first6 = Yong-Joon , last7 = Park , first7 = Sun , last8 = Shin , first8 = Ho-Joon , last9 = Kim , first9 = Kyongmin , journal = Journal of Virology , volume = 93 , issue = 6 , pmid = 30567987 , pmc = 6401437 Using

photoaffinity labeling Photoaffinity labeling is a chemoproteomics technique used to attach "labels" to the active site of a large molecule, especially a protein. The "label" attaches to the molecule loosely and reversibly, and has an inactive site which can be converted ...

and

liquid chromatography–mass spectrometry Liquid chromatography–mass spectrometry (LC–MS) is an analytical chemistry technique that combines the physical separation capabilities of liquid chromatography (or High performance liquid chromatography, HPLC) with the mass analysis capabil ...

analysis, Par17 was found to be associated with mitochondrial proteins such as members of the electron transport chain in human cells.

References

EC 5.2.1