ID   MRNC_SYNP1              Reviewed;         146 AA.
AC   Q05370;
DT   01-FEB-1994, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1994, sequence version 1.
DT   25-MAY-2022, entry version 63.
DE   RecName: Full=Mini-ribonuclease 3 {ECO:0000255|HAMAP-Rule:MF_01468};
DE            Short=Mini-3 {ECO:0000255|HAMAP-Rule:MF_01468};
DE            Short=Mini-RNase 3 {ECO:0000255|HAMAP-Rule:MF_01468};
DE            EC=3.1.26.- {ECO:0000255|HAMAP-Rule:MF_01468};
DE   AltName: Full=Mini-RNase III {ECO:0000255|HAMAP-Rule:MF_01468};
DE            Short=Mini-III {ECO:0000255|HAMAP-Rule:MF_01468};
DE   AltName: Full=URF4;
GN   Name=mrnC {ECO:0000255|HAMAP-Rule:MF_01468};
OS   Synechococcus sp. (strain PCC 6716).
OC   Bacteria; Cyanobacteria; Synechococcales; Synechococcaceae; Synechococcus;
OC   unclassified Synechococcus.
OX   NCBI_TaxID=32048;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=8363578; DOI=10.1042/bj2940239;
RA   van Walraven H.S., Lutter R., Walker J.E.;
RT   "Organization and sequences of genes for the subunits of ATP synthase in
RT   the thermophilic cyanobacterium Synechococcus 6716.";
RL   Biochem. J. 294:239-251(1993).
CC   -!- FUNCTION: Involved in correct processing of both the 5' and 3' ends of
CC       23S rRNA precursor. Processes 30S rRNA precursor transcript even if
CC       ribonuclease 3 (Rnc) is inactivated; Rnc processes 30S rRNA into
CC       smaller rRNA precursors (By similarity). {ECO:0000250}.
CC   -!- COFACTOR:
CC       Name=Mg(2+); Xref=ChEBI:CHEBI:18420;
CC   -!- SUBUNIT: Homodimer. {ECO:0000255|HAMAP-Rule:MF_01468}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000255|HAMAP-Rule:MF_01468}.
CC   -!- SIMILARITY: Belongs to the MrnC RNase family. {ECO:0000255|HAMAP-
CC       Rule:MF_01468}.
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DR   EMBL; X70431; CAA49880.1; -; Genomic_DNA.
DR   AlphaFoldDB; Q05370; -.
DR   SMR; Q05370; -.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0004525; F:ribonuclease III activity; IEA:InterPro.
DR   GO; GO:0019843; F:rRNA binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0006364; P:rRNA processing; IEA:UniProtKB-UniRule.
DR   CDD; cd00593; RIBOc; 1.
DR   Gene3D; 1.10.1520.10; -; 1.
DR   HAMAP; MF_01468; RNase_Mini_III; 1.
DR   InterPro; IPR008226; Mini3_fam.
DR   InterPro; IPR000999; RNase_III_dom.
DR   InterPro; IPR036389; RNase_III_sf.
DR   Pfam; PF00636; Ribonuclease_3; 1.
DR   PIRSF; PIRSF005520; UCP005520; 1.
DR   SMART; SM00535; RIBOc; 1.
DR   SUPFAM; SSF69065; SSF69065; 1.
PE   3: Inferred from homology;
KW   Cytoplasm; Endonuclease; Hydrolase; Magnesium; Nuclease;
KW   Ribosome biogenesis; RNA-binding; rRNA processing; rRNA-binding.
FT   CHAIN           1..146
FT                   /note="Mini-ribonuclease 3"
FT                   /id="PRO_0000066134"
FT   ACT_SITE        32
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01468"
SQ   SEQUENCE   146 AA;  16326 MW;  DB2DC5A17685DA2D CRC64;
     MVMMASAPFL PIVSDAIAAQ RLSPSALAYF GDAVYELFIR FIFLTPPQRI NAYHHQVVAH
     VRAESQARYM DILWPHCTAA ELTIFRQGRN AAADGPKRVP AKIYRQATGF EALLGYLYLT
     DPQRLQDVLA LLEQHIRAEV AAAESL