ID   RSMI_SYNY3              Reviewed;         279 AA.
AC   P74038;
DT   01-NOV-1997, integrated into UniProtKB/Swiss-Prot.
DT   01-FEB-1997, sequence version 1.
DT   04-NOV-2026, entry version 133.
DE   RecName: Full=Ribosomal RNA small subunit methyltransferase I {ECO:0000255|HAMAP-Rule:MF_01877};
DE            EC=2.1.1.198 {ECO:0000255|HAMAP-Rule:MF_01877};
DE   AltName: Full=16S rRNA 2'-O-ribose C1402 methyltransferase {ECO:0000255|HAMAP-Rule:MF_01877};
DE   AltName: Full=rRNA (cytidine-2'-O-)-methyltransferase RsmI {ECO:0000255|HAMAP-Rule:MF_01877};
GN   Name=rsmI {ECO:0000255|HAMAP-Rule:MF_01877};
GN   OrderedLocusNames=sll0818;
OS   Synechocystis sp. (strain ATCC 27184 / PCC 6803 / Kazusa).
OC   Bacteria; Bacillati; Cyanobacteriota; Cyanophyceae; Synechococcales;
OC   Merismopediaceae; Synechocystis.
OX   NCBI_TaxID=1111708;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC 27184 / PCC 6803 / Kazusa;
RX   PubMed=8905231; DOI=10.1093/dnares/3.3.109;
RA   Kaneko T., Sato S., Kotani H., Tanaka A., Asamizu E., Nakamura Y.,
RA   Miyajima N., Hirosawa M., Sugiura M., Sasamoto S., Kimura T., Hosouchi T.,
RA   Matsuno A., Muraki A., Nakazaki N., Naruo K., Okumura S., Shimpo S.,
RA   Takeuchi C., Wada T., Watanabe A., Yamada M., Yasuda M., Tabata S.;
RT   "Sequence analysis of the genome of the unicellular cyanobacterium
RT   Synechocystis sp. strain PCC6803. II. Sequence determination of the entire
RT   genome and assignment of potential protein-coding regions.";
RL   DNA Res. 3:109-136(1996).
CC   -!- FUNCTION: Catalyzes the 2'-O-methylation of the ribose of cytidine 1402
CC       (C1402) in 16S rRNA. {ECO:0000255|HAMAP-Rule:MF_01877}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=cytidine(1402) in 16S rRNA + S-adenosyl-L-methionine = 2'-O-
CC         methylcytidine(1402) in 16S rRNA + S-adenosyl-L-homocysteine + H(+);
CC         Xref=Rhea:RHEA:42924, Rhea:RHEA-COMP:10285, Rhea:RHEA-COMP:10286,
CC         ChEBI:CHEBI:15378, ChEBI:CHEBI:57856, ChEBI:CHEBI:59789,
CC         ChEBI:CHEBI:74495, ChEBI:CHEBI:82748; EC=2.1.1.198;
CC         Evidence={ECO:0000255|HAMAP-Rule:MF_01877};
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000255|HAMAP-Rule:MF_01877}.
CC   -!- SIMILARITY: Belongs to the methyltransferase superfamily. RsmI family.
CC       {ECO:0000255|HAMAP-Rule:MF_01877}.
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DR   EMBL; BA000022; BAA18113.1; -; Genomic_DNA.
DR   PIR; S75552; S75552.
DR   AlphaFoldDB; P74038; -.
DR   SMR; P74038; -.
DR   FunCoup; P74038; 381.
DR   IntAct; P74038; 1.
DR   STRING; 1148.gene:10498984; -.
DR   PaxDb; 1148-gene:10498984; -.
DR   EnsemblBacteria; BAA18113; BAA18113; BAA18113.
DR   KEGG; syn:sll0818; -.
DR   eggNOG; COG0313; Bacteria.
DR   InParanoid; P74038; -.
DR   OMA; AACHEHN; -.
DR   PhylomeDB; P74038; -.
DR   Proteomes; UP000001425; Chromosome.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0070677; F:rRNA (cytosine-2'-O-ribose)-methyltransferase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0004851; F:uroporphyrin-III C-methyltransferase activity; IBA:GO_Central.
DR   GO; GO:0031167; P:rRNA methylation; IEA:UniProtKB-UniRule.
DR   GO; GO:0019354; P:siroheme biosynthetic process; IBA:GO_Central.
DR   CDD; cd11648; RsmI; 1.
DR   FunFam; 3.30.950.10:FF:000002; Ribosomal RNA small subunit methyltransferase I; 1.
DR   FunFam; 3.40.1010.10:FF:000002; Ribosomal RNA small subunit methyltransferase I; 1.
DR   Gene3D; 3.40.1010.10; Cobalt-precorrin-4 Transmethylase, Domain 1; 1.
DR   Gene3D; 3.30.950.10; Methyltransferase, Cobalt-precorrin-4 Transmethylase, Domain 2; 1.
DR   HAMAP; MF_01877; 16SrRNA_methyltr_I; 1.
DR   InterPro; IPR000878; 4pyrrol_Mease.
DR   InterPro; IPR035996; 4pyrrol_Methylase_sf.
DR   InterPro; IPR014777; 4pyrrole_Mease_sub1.
DR   InterPro; IPR014776; 4pyrrole_Mease_sub2.
DR   InterPro; IPR008189; rRNA_ssu_MeTfrase_I.
DR   InterPro; IPR018063; SAM_MeTrfase_RsmI_CS.
DR   NCBIfam; TIGR00096; 16S rRNA (cytidine(1402)-2'-O)-methyltransferase; 1.
DR   PANTHER; PTHR46111; RIBOSOMAL RNA SMALL SUBUNIT METHYLTRANSFERASE I; 1.
DR   PANTHER; PTHR46111:SF1; RIBOSOMAL RNA SMALL SUBUNIT METHYLTRANSFERASE I; 1.
DR   Pfam; PF00590; TP_methylase; 1.
DR   PIRSF; PIRSF005917; MTase_YraL; 1.
DR   SUPFAM; SSF53790; Tetrapyrrole methylase; 1.
DR   PROSITE; PS01296; RSMI; 1.
PE   3: Inferred from homology;
KW   Cytoplasm; Methyltransferase; Reference proteome; rRNA processing;
KW   S-adenosyl-L-methionine; Transferase.
FT   CHAIN           1..279
FT                   /note="Ribosomal RNA small subunit methyltransferase I"
FT                   /id="PRO_0000211958"
SQ   SEQUENCE   279 AA;  30830 MW;  102BE57BF582F519 CRC64;
     MGILYLVATP IGNLGDMTPR AVETLQTVDL IAAEDTRHTG KLLQHFQITT PQISYHDHNR
     HGRTQELLAK LQAGQNIALV SDAGTPGISD PGQELVAACG EANIEVIPIP GATALIAALI
     SSGLATDRFV FEGFLSTKNR PRQQLLQSLA QEERTIILYE APHRLLATLT DLQTFLGQER
     SLTVARELTK YHEQFWRGTL QTAIAYFTEN TPKGEFCLVI AGATPEDRPS FSEENLRDEL
     RSLMAKGLTR SQASRQLAEE TKLPRRQLYQ LSLELEADG
//