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HAMAP rule MF_01261

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General rule information [?]

Accession MF_01261
Dates 29-JUL-2005 (Created)
17-MAY-2023 (Last updated, Version 24)
Name CCA_bact_type1
Scope(s) Bacteria
Template(s) P06961 (CCA_ECOLI); Q7SIB1 (CCA_GEOSE); [ Recover all ]
Triggered by HAMAP; MF_01261 (Get profile general information and statistics)

Propagated annotation [?]

Identifier, protein and gene names [?]

Identifier CCA
Protein name RecName: Full=Multifunctional CCA protein;
RecName: Full=CCA-adding enzyme;
AltName: Full=CCA tRNA nucleotidyltransferase;
AltName: Full=tRNA CCA-pyrophosphorylase;
AltName: Full=tRNA adenylyl-/cytidylyl-transferase;
AltName: Full=tRNA nucleotidyltransferase;
AltName: Full=tRNA-NT;
RecName: Full=2'-nucleotidase;
RecName: Full=2',3'-cyclic phosphodiesterase;
RecName: Full=Phosphatase;
Gene name Name=cca;

Comments [?]

FUNCTIONCatalyzes the addition and repair of the essential 3'- terminal CCA sequence in tRNAs without using a nucleic acid template. Adds these three nucleotides in the order of C, C, and A to the tRNA nucleotide-73, using CTP and ATP as substrates and producing inorganic pyrophosphate. tRNA 3'-terminal CCA addition is required both for tRNA processing and repair. Also involved in tRNA surveillance by mediating tandem CCA addition to generate a CCACCA at the 3' terminus of unstable tRNAs. While stable tRNAs receive only 3'-terminal CCA, unstable tRNAs are marked with CCACCA and rapidly degraded.
CATALYTIC ACTIVITY Reaction=a tRNA precursor + ATP + 2 CTP = a tRNA with a 3' CCA end + 3 diphosphate; Xref=Rhea:RHEA:14433, Rhea:RHEA-COMP:10465, Rhea:RHEA- COMP:10468, ChEBI:CHEBI:30616, ChEBI:CHEBI:33019, ChEBI:CHEBI:37563, ChEBI:CHEBI:74896, ChEBI:CHEBI:83071; EC=;
CATALYTIC ACTIVITY Reaction=a tRNA with a 3' CCA end + ATP + 2 CTP = a tRNA with a 3' CCACCA end + 3 diphosphate; Xref=Rhea:RHEA:76235, Rhea:RHEA- COMP:10468, Rhea:RHEA-COMP:18655, ChEBI:CHEBI:30616, ChEBI:CHEBI:33019, ChEBI:CHEBI:37563, ChEBI:CHEBI:83071, ChEBI:CHEBI:195187; PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:76236;
COFACTOR Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Note=Magnesium is required for nucleotidyltransferase activity.;
COFACTOR Name=Ni(2+); Xref=ChEBI:CHEBI:49786; Note=Nickel for phosphatase activity.;
SUBUNITMonomer. Can also form homodimers and oligomers.
DOMAINComprises two domains: an N-terminal domain containing the nucleotidyltransferase activity and a C-terminal HD domain associated with both phosphodiesterase and phosphatase activities.
MISCELLANEOUSA single active site specifically recognizes both ATP and CTP and is responsible for their addition.
SIMILARITYBelongs to the tRNA nucleotidyltransferase/poly(A) polymerase family. Bacterial CCA-adding enzyme type 1 subfamily.

Keywords [?]

Gene Ontology [?]

GO:0000049; Molecular function:tRNA binding
GO:0000166; Molecular function:nucleotide binding
GO:0000287; Molecular function:magnesium ion binding
GO:0004112; Molecular function:cyclic-nucleotide phosphodiesterase activity
GO:0004810; Molecular function:CCA tRNA nucleotidyltransferase activity
GO:0005524; Molecular function:ATP binding
GO:0016791; Molecular function:phosphatase activity
GO:0001680; Biological process:tRNA 3'-terminal CCA addition

Cross-references [?]

Pfam PF01966; HD; 1;
Pfam PF01743; PolyA_pol; 1;
PROSITE PS51831; HD; 1;

Features [?]

From: CCA_ECOLI (P06961)
Key From To Description Tag Condition FTGroup
BINDING 21 21 /ligand="Mg(2+)"
BINDING 23 23 /ligand="Mg(2+)"
BINDING 8 8 /ligand="ATP"
BINDING 8 8 /ligand="CTP"
BINDING 11 11 /ligand="ATP"
BINDING 11 11 /ligand="CTP"
BINDING 91 91 /ligand="ATP"
BINDING 91 91 /ligand="CTP"
BINDING 137 137 /ligand="ATP"
BINDING 137 137 /ligand="CTP"
BINDING 140 140 /ligand="ATP"
BINDING 140 140 /ligand="CTP"

Additional information [?]

Size range 368-429 amino acids
Related rules MF_01262
Fusion Nter: None Cter: None
Comments The CCA-adding enzyme family consists of 4 different subfamilies: 3 bacterial subfamilies (MF_01261, MF_01262 and MF_01263) and 1 archaeal subfamily (MF_01264). FT lines are propagated from G.stearothermophilus CCA-adding enzyme (type 3 subfamily, MF_01263) whose X-ray structure is known.

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