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Annotation rule MF_01262 |
Accession | MF_01262 |
Dates | 29-JUL-2005 (Created) 19-NOV-2019 (Last updated, Version 12) |
Name | CCA_bact_type2 |
Scope | Bacteria; Proteobacteria |
Templates | P06961 (CCA_ECOLI); Q7SIB1 (CCA_GEOSE): [Recover all] |
Triggered by |
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Protein name |
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Gene name |
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Function | 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. |
Catalytic activity | RHEA:14433: a tRNA precursor + ATP + 2 CTP = a tRNA with a 3' CCA end + 3 diphosphate
EC 2.7.7.72 |
Cofactor | Mg(2+) |
Miscellaneous | A single active site specifically recognizes both ATP and CTP and is responsible for their addition. |
Similarity | Belongs to the tRNA nucleotidyltransferase/poly(A) polymerase family. Bacterial CCA-adding enzyme type 2 subfamily. |
Pfam | PF01743; PolyA_pol; 1; |
From: CCA_BUCAI (P57169) | ||||||||||||
Key | From | To | Description | Tag | Condition | FTGroup | ||||||
METAL | 21 | 21 | Magnesium | [DE] | ||||||||
METAL | 23 | 23 | Magnesium | D | ||||||||
BINDING | 8 | 8 | ATP or CTP; via amide nitrogen | G | ||||||||
BINDING | 11 | 11 | ATP or CTP | R | ||||||||
BINDING | 91 | 91 | ATP or CTP | R | ||||||||
BINDING | 137 | 137 | ATP or CTP | R | ||||||||
BINDING | 140 | 140 | ATP or CTP | R |
Size range | 360-419 amino acids |
Related rules | MF_01261 (CCA supersedes the current rule) |
Fusion | 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). There is no characterized protein in this subfamily. The closest sequence homologs are from type 1 subfamily (MF_01261), which is also a proteobacterial family (E.coli is characterized) but which contains an HD domain associated with phosphohydrolase activities. As the type 2 subfamily does not contain such a domain, it should not possess phosphohydrolase activities. FT lines are propagated from B.stearothermophilus CCA-adding enzyme (type 3 subfamily, MF_01263) whose X-ray structure is known. |