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Nucleotidyltransferases are
Nucleotidyltransferases are transferase
A transferase is any one of a class of enzymes that catalyse the transfer of specific functional groups (e.g. a methyl or glycosyl group) from one molecule (called the donor) to another (called the acceptor). They are involved in hundreds of di ...
enzymes of phosphorus-containing groups, e.g., substituent
A substituent is one or a group of atoms that replaces (one or more) atoms, thereby becoming a moiety in the resultant (new) molecule. (In organic chemistry and biochemistry, the terms ''substituent'' and ''functional group'', as well as ''side ...
s of nucleotidylic acids or simply nucleoside monophosphates. The general reaction of transferring a nucleoside monophosphate moiety from A to B, can be written as:
:A-P-N + B A + B-P-N
For example, in the case of polymerases, A is pyrophosphate and B is the nascent polynucleotide.
They are classified under EC number 2.7.7 and they can be categorised into:
#Uridylyltransferase
Nucleotidyltransferases are transferase enzymes of phosphorus-containing groups, e.g., substituents of nucleotidylic acids or simply nucleoside monophosphates. The general reaction of transferring a nucleoside monophosphate moiety from A to B, can ...
s, which transfer uridylyl- groups
# Adenylyltransferases, which transfer adenylyl
Adenosine monophosphate (AMP), also known as 5'-adenylic acid, is a nucleotide. AMP consists of a phosphate group, the sugar ribose, and the nucleobase adenine; it is an ester of phosphoric acid and the nucleoside adenosine. As a substituent it t ...
- groups
#Guanylyltransferase Guanylyl transferases are enzymes that transfer a guanosine mono phosphate group, usually from GTP to another molecule, releasing pyrophosphate. Many eukaryotic guanylyl transferases are capping enzymes that catalyze the formation of the 5' cap in ...
s, which transfer guanylyl
Guanosine monophosphate (GMP), also known as 5′-guanidylic acid or guanylic acid (conjugate base guanylate), is a nucleotide that is used as a monomer in RNA. It is an ester of phosphoric acid with the nucleoside guanosine. GMP consists of the ...
- groups
# Cytitidylyltransferases, which transfer cytidylyl- groups
# Thymidylyltransferases, which transfer thymidylyl
Thymidine monophosphate (TMP), also known as thymidylic acid (conjugate base thymidylate), deoxythymidine monophosphate (dTMP), or deoxythymidylic acid (conjugate base deoxythymidylate), is a nucleotide that is used as a monomer in DNA. It is an ...
- groups
Role in metabolism
Many metabolic enzymes are modified by nucleotidyltransferases. The attachment of anAMP #REDIRECT Amp
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(adenylylation) or UMP (uridylylation) can activate or inactivate an enzyme or change its specificity (see figure). These modifications can lead to intricate regulatory networks that can finely tune enzymatic
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...
activities so that only the needed compounds are made (here: glutamine).
Role in DNA repair mechanisms
Nucleotidyl transferase is a component of the repair pathway for single nucleotidebase excision repair
Base excision repair (BER) is a cellular mechanism, studied in the fields of biochemistry and genetics, that repairs damaged DNA throughout the cell cycle. It is responsible primarily for removing small, non-helix-distorting base lesions from t ...
. This repair mechanism begins when a single nucleotide is recognized by DNA glycosylase Glycosylases ( EC 3.2) are enzymes that hydrolyze glycosyl compounds. They are a type of hydrolase (EC 3). In turn, glycosylases are divided into two groups: glycosidase
Glycoside hydrolases (also called glycosidases or glycosyl hydrolases) ca ...
as incorrectly matched or has been mutated in some way (UV light, chemical mutagen, etc.), and is removed. Later, a nucleotidyl transferase is used to fill in the gap with the correct base, using the template strand
Transcription is the process of copying a segment of DNA into RNA. The segments of DNA transcribed into RNA molecules that can encode proteins are said to produce messenger RNA (mRNA). Other segments of DNA are copied into RNA molecules called ...
as the reference.
References
External links
* Transferases * {{2.7-enzyme-stub