UniProtKB - P06961 (CCA_ECOLI)
Protein
Multifunctional CCA protein
Gene
cca
Organism
Escherichia coli (strain K12)
Status
Functioni
Catalyzes 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. Also shows highest phosphatase activity in the presence of Ni2+ and hydrolyzes pyrophosphate, canonical 5'-nucleoside tri- and diphosphates, NADP, and 2'-AMP with the production of Pi. Displays a metal-independent phosphodiesterase activity toward 2',3'-cAMP, 2',3'-cGMP, and 2',3'-cCMP. Without metal or in the presence of Mg2+, this protein hydrolyzes 2',3'-cyclic substrates with the formation of 2'-nucleotides, whereas in the presence of Ni2+, it also produces some 3'-nucleotides. These phosphohydrolase activities are probably involved in the repair of the tRNA 3'-CCA terminus degraded by intracellular RNases.1 Publication
Miscellaneous
A single active site specifically recognizes both ATP and CTP and is responsible for their addition.By similarity
Catalytic activityi
- EC:2.7.7.72
Cofactori
Protein has several cofactor binding sites:- Mg2+Note: Magnesium is required for nucleotidyltransferase activity.
- Ni2+Note: Nickel for phosphatase activity.
Activity regulationi
Both phosphatase and phosphodiesterase activities are competitively inhibited by low concentrations of the E.coli tRNA (10 nM). Cu2+ stimulates the hydrolysis of pyrophosphate and ATP and completely inhibits the hydrolysis of 2'-AMP. The phosphodiesterase activity is inhibited by Zn2+, Cu2+ and Co2+.
Kineticsi
- KM=0.33 mM for ATP (in the tRNA-NT activity assay)2 Publications
- KM=0.03 mM for CTP (in the tRNA-NT activity assay)2 Publications
- KM=0.015 mM for tRNA-CC2 Publications
- KM=0.02 mM for tRNA-C2 Publications
- KM=6.2 mM for pNPP2 Publications
- KM=0.10 mM for PPi2 Publications
- KM=0.15 mM for NADP2 Publications
- KM=0.19 mM for ADP2 Publications
- KM=0.18 mM for ATP (in the phosphatase activity assay)2 Publications
- KM=0.53 mM for CDP2 Publications
- KM=0.13 mM for CTP (in the phosphatase activity assay)2 Publications
- KM=0.76 mM for 2'-AMP2 Publications
- KM=0.49 mM for 2',3'-cAMP2 Publications
- KM=1.60 mM for 2',3'-cGMP2 Publications
- Vmax=12.4 µmol/min/mg enzyme with pNPP as substrate2 Publications
- Vmax=3.01 µmol/min/mg enzyme with PPi as substrate2 Publications
- Vmax=17.9 µmol/min/mg enzyme with NADP as substrate2 Publications
- Vmax=1.49 µmol/min/mg enzyme with ADP as substrate2 Publications
- Vmax=4.53 µmol/min/mg enzyme with ATP as substrate (in the phosphatase activity assay)2 Publications
- Vmax=5.80 µmol/min/mg enzyme with CDP as substrate2 Publications
- Vmax=4.03 µmol/min/mg enzyme with CTP as substrate (in the phosphatase activity assay)2 Publications
- Vmax=3.71 µmol/min/mg enzyme with 2'-AMP as substrate2 Publications
- Vmax=3.21 µmol/min/mg enzyme with 2',3'-cAMP as substrate2 Publications
- Vmax=2.36 µmol/min/mg enzyme with 2',3'-cGMP as substrate2 Publications
pH dependencei
Optimum pH is 9.4 for AMP incorporation, 10.0 for CMP incorporation, and 7.0 for the phosphatase and phosphodiesterase activities.2 Publications
Sites
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Binding sitei | 8 | ATP or CTP; via amide nitrogenBy similarity | 1 | |
Binding sitei | 11 | ATP or CTPBy similarity | 1 | |
Metal bindingi | 21 | MagnesiumBy similarity | 1 | |
Metal bindingi | 23 | MagnesiumBy similarity | 1 | |
Binding sitei | 91 | ATP or CTPBy similarity | 1 | |
Binding sitei | 137 | ATP or CTPBy similarity | 1 | |
Binding sitei | 140 | ATP or CTPBy similarity | 1 |
GO - Molecular functioni
- ATP:3'-cytidine-cytidine-tRNA adenylyltransferase activity Source: UniProtKB-EC
- ATP binding Source: UniProtKB-UniRule
- CTP:3'-cytidine-tRNA cytidylyltransferase activity Source: UniProtKB-EC
- CTP:tRNA cytidylyltransferase activity Source: UniProtKB-EC
- cyclic-nucleotide phosphodiesterase activity Source: EcoCyc
- magnesium ion binding Source: UniProtKB-UniRule
- phosphatase activity Source: UniProtKB-UniRule
- tRNA adenylyltransferase activity Source: EcoCyc
- tRNA binding Source: UniProtKB-UniRule
- tRNA cytidylyltransferase activity Source: EcoCyc
GO - Biological processi
- RNA repair Source: EcoCyc
- tRNA 3'-terminal CCA addition Source: EcoCyc
Keywordsi
Molecular function | Hydrolase, Multifunctional enzyme, Nucleotidyltransferase, RNA-binding, Transferase |
Biological process | RNA repair, tRNA processing |
Ligand | ATP-binding, Magnesium, Metal-binding, Nickel, Nucleotide-binding |
Enzyme and pathway databases
BioCyci | EcoCyc:EG10136-MONOMER MetaCyc:EG10136-MONOMER |
BRENDAi | 2.7.7.72, 2026 3.1.4.16, 2026 3.1.4.37, 2026 |
SABIO-RKi | P06961 |
Names & Taxonomyi
Protein namesi | Recommended name: Multifunctional CCA proteinIncluding the following 4 domains: |
Gene namesi | Name:cca Ordered Locus Names:b3056, JW3028 |
Organismi | Escherichia coli (strain K12) |
Taxonomic identifieri | 83333 [NCBI] |
Taxonomic lineagei | Bacteria › Proteobacteria › Gammaproteobacteria › Enterobacterales › Enterobacteriaceae › Escherichia › |
Proteomesi |
|
Pathology & Biotechi
Mutagenesis
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Mutagenesisi | 21 | D → A: No effect on phosphodiesterase and phosphatase activities. 1 Publication | 1 | |
Mutagenesisi | 23 | D → A: No effect on phosphodiesterase and phosphatase activities. 1 Publication | 1 | |
Mutagenesisi | 70 | G → D: Lowered AMP incorporation. 1 Publication | 1 | |
Mutagenesisi | 255 | H → A: Loss of phosphodiesterase and phosphatase activities. 1 Publication | 1 | |
Mutagenesisi | 256 | D → A: Loss of phosphodiesterase and phosphatase activities. 1 Publication | 1 | |
Mutagenesisi | 305 | H → A: Loss of phosphodiesterase and phosphatase activities. 1 Publication | 1 | |
Mutagenesisi | 306 | D → A: Still possesses phosphodiesterase and phosphatase activities. 1 Publication | 1 |
Chemistry databases
ChEMBLi | CHEMBL3309020 |
PTM / Processingi
Molecule processing
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
ChainiPRO_0000138975 | 1 – 412 | Multifunctional CCA proteinAdd BLAST | 412 |
Proteomic databases
jPOSTi | P06961 |
PaxDbi | P06961 |
PRIDEi | P06961 |
Interactioni
Subunit structurei
Monomer. Can also form homodimers and oligomers, but with low levels.
1 PublicationBinary interactionsi
P06961
With | #Exp. | IntAct |
---|---|---|
dtd [P0A6M4] | 2 | EBI-545256,EBI-562575 |
Protein-protein interaction databases
BioGRIDi | 4259255, 71 interactors |
DIPi | DIP-9250N |
IntActi | P06961, 25 interactors |
STRINGi | 511145.b3056 |
Family & Domainsi
Domains and Repeats
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Domaini | 228 – 329 | HDPROSITE-ProRule annotationAdd BLAST | 102 |
Domaini
Comprises two domains: an N-terminal domain containing the nucleotidyltransferase activity and a C-terminal HD domain associated with both phosphodiesterase and phosphatase activities.
Sequence similaritiesi
Belongs to the tRNA nucleotidyltransferase/poly(A) polymerase family. Bacterial CCA-adding enzyme type 1 subfamily.Curated
Phylogenomic databases
eggNOGi | COG0617, Bacteria |
HOGENOMi | CLU_015961_1_1_6 |
InParanoidi | P06961 |
PhylomeDBi | P06961 |
Family and domain databases
CDDi | cd00077, HDc, 1 hit cd05398, NT_ClassII-CCAase, 1 hit |
Gene3Di | 3.30.460.10, 1 hit |
HAMAPi | MF_01261, CCA_bact_type1, 1 hit MF_01262, CCA_bact_type2, 1 hit |
InterProi | View protein in InterPro IPR012006, CCA_bact IPR003607, HD/PDEase_dom IPR006674, HD_domain IPR043519, NT_sf IPR002646, PolA_pol_head_dom IPR032828, PolyA_RNA-bd |
Pfami | View protein in Pfam PF01966, HD, 1 hit PF01743, PolyA_pol, 1 hit PF12627, PolyA_pol_RNAbd, 1 hit |
PIRSFi | PIRSF000813, CCA_bact, 1 hit |
SUPFAMi | SSF81301, SSF81301, 1 hit |
PROSITEi | View protein in PROSITE PS51831, HD, 1 hit |
i Sequence
Sequence statusi: Complete.
P06961-1 [UniParc]FASTAAdd to basket
10 20 30 40 50
MKIYLVGGAV RDALLGLPVK DRDWVVVGST PQEMLDAGYQ QVGRDFPVFL
60 70 80 90 100
HPQTHEEYAL ARTERKSGSG YTGFTCYAAP DVTLEDDLKR RDLTINALAQ
110 120 130 140 150
DDNGEIIDPY NGLGDLQNRL LRHVSPAFGE DPLRVLRVAR FAARYAHLGF
160 170 180 190 200
RIADETLALM REMTHAGELE HLTPERVWKE TESALTTRNP QVFFQVLRDC
210 220 230 240 250
GALRVLFPEI DALFGVPAPA KWHPEIDTGI HTLMTLSMAA MLSPQVDVRF
260 270 280 290 300
ATLCHDLGKG LTPPELWPRH HGHGPAGVKL VEQLCQRLRV PNEIRDLARL
310 320 330 340 350
VAEFHDLIHT FPMLNPKTIV KLFDSIDAWR KPQRVEQLAL TSEADVRGRT
360 370 380 390 400
GFESADYPQG RWLREAWEVA QSVPTKAVVE AGFKGVEIRE ELTRRRIAAV
410
ASWKEQRCPK PE
Sequence databases
Select the link destinations: EMBLi GenBanki DDBJi Links Updated | M12788 Genomic DNA Translation: AAA23541.1 U28379 Genomic DNA Translation: AAA89136.1 U00096 Genomic DNA Translation: AAC76092.1 AP009048 Genomic DNA Translation: BAE77107.1 |
PIRi | A25215, RNECTA |
RefSeqi | NP_417528.1, NC_000913.3 WP_000708487.1, NZ_STEB01000001.1 |
Genome annotation databases
EnsemblBacteriai | AAC76092; AAC76092; b3056 BAE77107; BAE77107; BAE77107 |
GeneIDi | 57728183 947553 |
KEGGi | ecj:JW3028 eco:b3056 |
PATRICi | fig|1411691.4.peg.3675 |
Similar proteinsi
Cross-referencesi
Sequence databases
Select the link destinations: EMBLi GenBanki DDBJi Links Updated | M12788 Genomic DNA Translation: AAA23541.1 U28379 Genomic DNA Translation: AAA89136.1 U00096 Genomic DNA Translation: AAC76092.1 AP009048 Genomic DNA Translation: BAE77107.1 |
PIRi | A25215, RNECTA |
RefSeqi | NP_417528.1, NC_000913.3 WP_000708487.1, NZ_STEB01000001.1 |
3D structure databases
SMRi | P06961 |
ModBasei | Search... |
Protein-protein interaction databases
BioGRIDi | 4259255, 71 interactors |
DIPi | DIP-9250N |
IntActi | P06961, 25 interactors |
STRINGi | 511145.b3056 |
Chemistry databases
ChEMBLi | CHEMBL3309020 |
Proteomic databases
jPOSTi | P06961 |
PaxDbi | P06961 |
PRIDEi | P06961 |
Genome annotation databases
EnsemblBacteriai | AAC76092; AAC76092; b3056 BAE77107; BAE77107; BAE77107 |
GeneIDi | 57728183 947553 |
KEGGi | ecj:JW3028 eco:b3056 |
PATRICi | fig|1411691.4.peg.3675 |
Organism-specific databases
EchoBASEi | EB0134 |
Phylogenomic databases
eggNOGi | COG0617, Bacteria |
HOGENOMi | CLU_015961_1_1_6 |
InParanoidi | P06961 |
PhylomeDBi | P06961 |
Enzyme and pathway databases
BioCyci | EcoCyc:EG10136-MONOMER MetaCyc:EG10136-MONOMER |
BRENDAi | 2.7.7.72, 2026 3.1.4.16, 2026 3.1.4.37, 2026 |
SABIO-RKi | P06961 |
Miscellaneous databases
PROi | PR:P06961 |
Family and domain databases
CDDi | cd00077, HDc, 1 hit cd05398, NT_ClassII-CCAase, 1 hit |
Gene3Di | 3.30.460.10, 1 hit |
HAMAPi | MF_01261, CCA_bact_type1, 1 hit MF_01262, CCA_bact_type2, 1 hit |
InterProi | View protein in InterPro IPR012006, CCA_bact IPR003607, HD/PDEase_dom IPR006674, HD_domain IPR043519, NT_sf IPR002646, PolA_pol_head_dom IPR032828, PolyA_RNA-bd |
Pfami | View protein in Pfam PF01966, HD, 1 hit PF01743, PolyA_pol, 1 hit PF12627, PolyA_pol_RNAbd, 1 hit |
PIRSFi | PIRSF000813, CCA_bact, 1 hit |
SUPFAMi | SSF81301, SSF81301, 1 hit |
PROSITEi | View protein in PROSITE PS51831, HD, 1 hit |
ProtoNeti | Search... |
MobiDBi | Search... |
Entry informationi
Entry namei | CCA_ECOLI | |
Accessioni | P06961Primary (citable) accession number: P06961 Secondary accession number(s): Q2M9E9 | |
Entry historyi | Integrated into UniProtKB/Swiss-Prot: | April 1, 1988 |
Last sequence update: | April 1, 1988 | |
Last modified: | February 10, 2021 | |
This is version 176 of the entry and version 1 of the sequence. See complete history. | ||
Entry statusi | Reviewed (UniProtKB/Swiss-Prot) | |
Annotation program | Prokaryotic Protein Annotation Program |
Miscellaneousi
Keywords - Technical termi
Reference proteomeDocuments
- SIMILARITY comments
Index of protein domains and families