ID   VPK21_HUMAN             Reviewed;         156 AA.
AC   P63119;
DT   13-SEP-2004, integrated into UniProtKB/Swiss-Prot.
DT   13-SEP-2004, sequence version 1.
DT   03-AUG-2022, entry version 88.
DE   RecName: Full=Endogenous retrovirus group K member 21 Pro protein;
DE   AltName: Full=HERV-K_12q14.1 provirus ancestral Pro protein;
DE            EC=3.4.23.50;
DE   AltName: Full=Protease;
DE   AltName: Full=Proteinase;
DE            Short=PR;
GN   Name=ERVK-21;
OS   Homo sapiens (Human).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC   Eutheria; Euarchontoglires; Primates; Haplorrhini; Catarrhini; Hominidae;
OC   Homo.
OX   NCBI_TaxID=9606;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RX   PubMed=16541075; DOI=10.1038/nature04569;
RA   Scherer S.E., Muzny D.M., Buhay C.J., Chen R., Cree A., Ding Y.,
RA   Dugan-Rocha S., Gill R., Gunaratne P., Harris R.A., Hawes A.C.,
RA   Hernandez J., Hodgson A.V., Hume J., Jackson A., Khan Z.M., Kovar-Smith C.,
RA   Lewis L.R., Lozado R.J., Metzker M.L., Milosavljevic A., Miner G.R.,
RA   Montgomery K.T., Morgan M.B., Nazareth L.V., Scott G., Sodergren E.,
RA   Song X.-Z., Steffen D., Lovering R.C., Wheeler D.A., Worley K.C., Yuan Y.,
RA   Zhang Z., Adams C.Q., Ansari-Lari M.A., Ayele M., Brown M.J., Chen G.,
RA   Chen Z., Clerc-Blankenburg K.P., Davis C., Delgado O., Dinh H.H.,
RA   Draper H., Gonzalez-Garay M.L., Havlak P., Jackson L.R., Jacob L.S.,
RA   Kelly S.H., Li L., Li Z., Liu J., Liu W., Lu J., Maheshwari M.,
RA   Nguyen B.-V., Okwuonu G.O., Pasternak S., Perez L.M., Plopper F.J.H.,
RA   Santibanez J., Shen H., Tabor P.E., Verduzco D., Waldron L., Wang Q.,
RA   Williams G.A., Zhang J., Zhou J., Allen C.C., Amin A.G., Anyalebechi V.,
RA   Bailey M., Barbaria J.A., Bimage K.E., Bryant N.P., Burch P.E.,
RA   Burkett C.E., Burrell K.L., Calderon E., Cardenas V., Carter K., Casias K.,
RA   Cavazos I., Cavazos S.R., Ceasar H., Chacko J., Chan S.N., Chavez D.,
RA   Christopoulos C., Chu J., Cockrell R., Cox C.D., Dang M., Dathorne S.R.,
RA   David R., Davis C.M., Davy-Carroll L., Deshazo D.R., Donlin J.E.,
RA   D'Souza L., Eaves K.A., Egan A., Emery-Cohen A.J., Escotto M., Flagg N.,
RA   Forbes L.D., Gabisi A.M., Garza M., Hamilton C., Henderson N.,
RA   Hernandez O., Hines S., Hogues M.E., Huang M., Idlebird D.G., Johnson R.,
RA   Jolivet A., Jones S., Kagan R., King L.M., Leal B., Lebow H., Lee S.,
RA   LeVan J.M., Lewis L.C., London P., Lorensuhewa L.M., Loulseged H.,
RA   Lovett D.A., Lucier A., Lucier R.L., Ma J., Madu R.C., Mapua P.,
RA   Martindale A.D., Martinez E., Massey E., Mawhiney S., Meador M.G.,
RA   Mendez S., Mercado C., Mercado I.C., Merritt C.E., Miner Z.L., Minja E.,
RA   Mitchell T., Mohabbat F., Mohabbat K., Montgomery B., Moore N., Morris S.,
RA   Munidasa M., Ngo R.N., Nguyen N.B., Nickerson E., Nwaokelemeh O.O.,
RA   Nwokenkwo S., Obregon M., Oguh M., Oragunye N., Oviedo R.J., Parish B.J.,
RA   Parker D.N., Parrish J., Parks K.L., Paul H.A., Payton B.A., Perez A.,
RA   Perrin W., Pickens A., Primus E.L., Pu L.-L., Puazo M., Quiles M.M.,
RA   Quiroz J.B., Rabata D., Reeves K., Ruiz S.J., Shao H., Sisson I.,
RA   Sonaike T., Sorelle R.P., Sutton A.E., Svatek A.F., Svetz L.A.,
RA   Tamerisa K.S., Taylor T.R., Teague B., Thomas N., Thorn R.D., Trejos Z.Y.,
RA   Trevino B.K., Ukegbu O.N., Urban J.B., Vasquez L.I., Vera V.A.,
RA   Villasana D.M., Wang L., Ward-Moore S., Warren J.T., Wei X., White F.,
RA   Williamson A.L., Wleczyk R., Wooden H.S., Wooden S.H., Yen J., Yoon L.,
RA   Yoon V., Zorrilla S.E., Nelson D., Kucherlapati R., Weinstock G.,
RA   Gibbs R.A.;
RT   "The finished DNA sequence of human chromosome 12.";
RL   Nature 440:346-351(2006).
CC   -!- FUNCTION: Retroviral proteases have roles in the processing of the
CC       primary translation products and the maturation of the viral particle.
CC       Endogenous Pro proteins may have kept, lost or modified their original
CC       function during evolution.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Processing at the authentic HIV-1 PR recognition site and
CC         release of the mature p17 matrix and the p24 capsid protein, as a
CC         result of the cleavage of the -SQNY-|-PIVQ- cleavage site.;
CC         EC=3.4.23.50;
CC   -!- SUBUNIT: Active as a homodimer. {ECO:0000250}.
CC   -!- ALTERNATIVE PRODUCTS:
CC       Event=Ribosomal frameshifting; Named isoforms=1;
CC         Comment=This protein is synthesized as Gag-Pro and Gag-Pro-Pol
CC         polyprotein. These polyproteins are thought, by similarity with
CC         type-B retroviruses, to be generated by -1 frameshifts occurring at
CC         the Gag-Pro and Pro-Pol genes boundaries.;
CC       Name=1;
CC         IsoId=P63119-1; Sequence=Displayed;
CC   -!- PTM: Autoproteolytically processed at the N-terminus. Expected C-
CC       terminal autoprocessing not detected. The sequence shown is that of the
CC       processed Pro protein (By similarity). {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the peptidase A2 family. HERV class-II K(HML-2)
CC       subfamily. {ECO:0000305}.
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DR   EMBL; AC025420; -; NOT_ANNOTATED_CDS; Genomic_DNA.
DR   AlphaFoldDB; P63119; -.
DR   SMR; P63119; -.
DR   BioMuta; HGNC:39035; -.
DR   DMDM; 52000850; -.
DR   PRIDE; P63119; -.
DR   GeneCards; ERVK-21; -.
DR   HGNC; HGNC:39035; ERVK-21.
DR   neXtProt; NX_P63119; -.
DR   PhylomeDB; P63119; -.
DR   Pharos; P63119; Tdark.
DR   Proteomes; UP000005640; Unplaced.
DR   GO; GO:0004190; F:aspartic-type endopeptidase activity; IEA:UniProtKB-KW.
DR   GO; GO:0003676; F:nucleic acid binding; IEA:InterPro.
DR   GO; GO:0006508; P:proteolysis; IEA:UniProtKB-KW.
DR   CDD; cd05482; HIV_retropepsin_like; 1.
DR   Gene3D; 2.40.70.10; -; 1.
DR   InterPro; IPR001969; Aspartic_peptidase_AS.
DR   InterPro; IPR000467; G_patch_dom.
DR   InterPro; IPR001995; Peptidase_A2_cat.
DR   InterPro; IPR021109; Peptidase_aspartic_dom_sf.
DR   InterPro; IPR034170; Retropepsin-like_cat_dom.
DR   InterPro; IPR018061; Retropepsins.
DR   Pfam; PF01585; G-patch; 1.
DR   Pfam; PF00077; RVP; 1.
DR   SMART; SM00443; G_patch; 1.
DR   SUPFAM; SSF50630; SSF50630; 1.
DR   PROSITE; PS50175; ASP_PROT_RETROV; 1.
DR   PROSITE; PS00141; ASP_PROTEASE; 1.
DR   PROSITE; PS50174; G_PATCH; 1.
PE   3: Inferred from homology;
KW   Aspartyl protease; Autocatalytic cleavage; ERV; Hydrolase; Protease;
KW   Reference proteome; Ribosomal frameshifting; Transposable element.
FT   CHAIN           1..156
FT                   /note="Endogenous retrovirus group K member 21 Pro protein"
FT                   /id="PRO_0000199536"
FT   DOMAIN          21..96
FT                   /note="Peptidase A2"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00275"
FT   DOMAIN          111..156
FT                   /note="G-patch"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00092"
FT   ACT_SITE        26
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU10094"
SQ   SEQUENCE   156 AA;  17107 MW;  D39B72059B056702 CRC64;
     WASQVSENRP VCKAIIQGKQ FEGLVDTGAD VSIIALNQWP KNWPKQKAVT GLVGIGTASE
     VYQSTEILHC LGPDNQESTV QPMITSIPLN LWGRDLLQQW GAEITMPTPL YSPTSQKIMT
     KMGYIPGKGL GKNEDGIKVP VEAKINQKRE GIGYPF