ID   RNU1_USTSP              Reviewed;         105 AA.
AC   P07736;
DT   01-AUG-1988, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1994, sequence version 2.
DT   03-AUG-2022, entry version 78.
DE   RecName: Full=Guanyl-specific ribonuclease U1;
DE            Short=RNase U1;
DE            EC=4.6.1.24;
OS   Ustilago sphaerogena (Smut fungus).
OC   Eukaryota; Fungi; Dikarya; Basidiomycota; Ustilaginomycotina;
OC   Ustilaginomycetes; Ustilaginales; Ustilaginaceae; Ustilago.
OX   NCBI_TaxID=5271;
RN   [1]
RP   PROTEIN SEQUENCE, AND PYROGLUTAMATE FORMATION AT GLN-1.
RX   PubMed=3163689; DOI=10.1093/oxfordjournals.jbchem.a122267;
RA   Takahashi K., Hashimoto J.;
RT   "The amino acid sequence of ribonuclease U1, a guanine-specific
RT   ribonuclease from the fungus Ustilago sphaerogena.";
RL   J. Biochem. 103:313-320(1988).
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=[RNA] containing guanosine + H2O = an [RNA fragment]-3'-
CC         guanosine-3'-phosphate + a 5'-hydroxy-ribonucleotide-3'-[RNA
CC         fragment].; EC=4.6.1.24;
CC   -!- SIMILARITY: Belongs to the ribonuclease N1/T1 family. {ECO:0000305}.
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DR   PIR; A41445; A41445.
DR   AlphaFoldDB; P07736; -.
DR   SMR; P07736; -.
DR   GO; GO:0004521; F:endoribonuclease activity; IEA:InterPro.
DR   GO; GO:0016829; F:lyase activity; IEA:UniProtKB-KW.
DR   GO; GO:0046589; F:ribonuclease T1 activity; IEA:UniProtKB-EC.
DR   GO; GO:0003723; F:RNA binding; IEA:InterPro.
DR   InterPro; IPR000026; Gua-sp_ribonuclease_N1/T1/U2.
DR   InterPro; IPR016191; Ribonuclease/ribotoxin.
DR   Pfam; PF00545; Ribonuclease; 1.
DR   SUPFAM; SSF53933; SSF53933; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Endonuclease; Hydrolase; Lyase;
KW   Nuclease; Pyrrolidone carboxylic acid.
FT   CHAIN           1..105
FT                   /note="Guanyl-specific ribonuclease U1"
FT                   /id="PRO_0000137376"
FT   ACT_SITE        37
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        57
FT                   /note="Proton acceptor"
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        92
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000250"
FT   MOD_RES         1
FT                   /note="Pyrrolidone carboxylic acid"
FT                   /evidence="ECO:0000269|PubMed:3163689"
FT   DISULFID        8..103
FT                   /evidence="ECO:0000269|PubMed:3163689"
FT   DISULFID        51..87
FT                   /evidence="ECO:0000269|PubMed:3163689"
SQ   SEQUENCE   105 AA;  11157 MW;  6AB6C3117A4B727A CRC64;
     QGGVSVNCGG TYYSSTQVNR AINNAKSGQY SSTGYPHTYN NYEGFDFSDY CDGPYKEYPL
     KTSSSGYTGG SPGADRVVYD SNDGTFCGAI THTGASGNNF VQCSY