Search results
Results from the WOW.Com Content Network
Cytosine deamination can alter the genome's many regulatory functions; previously silenced transposable elements (TEs) may become transcriptionally active due to the loss of CPG sites. [3] TEs have been proposed to accelerate the mechanism of enhancer creation by providing extra DNA that is compatible with the host transcription factors that ...
Activation-induced cytidine deaminase, also known as AICDA, AID and single-stranded DNA cytosine deaminase, is a 24 kDa enzyme which in humans is encoded by the AICDA gene. [5] It creates mutations in DNA [6] [7] by deamination of cytosine base, which turns it into uracil (which is recognized as a thymine). In other words, it changes a C:G base ...
In enzymology, a cytosine deaminase (EC 3.5.4.1) is an enzyme that catalyzes the chemical reaction cytosine + H 2 O ⇌ {\displaystyle \rightleftharpoons } uracil + NH 3 Thus, the two substrates of this enzyme are cytosine [ 1 ] and H 2 O , whereas its two products are uracil and NH 3 .
Cytidine deaminase is an enzyme that in humans is encoded by the CDA gene. [5] [6] [7]This gene encodes an enzyme involved in pyrimidine salvaging. The encoded protein forms a homotetramer that catalyzes the irreversible hydrolytic deamination of cytidine and deoxycytidine to uridine and deoxyuridine, respectively.
Cytosine can also be methylated into 5-methylcytosine by an enzyme called DNA methyltransferase or be methylated and hydroxylated to make 5-hydroxymethylcytosine. The difference in rates of deamination of cytosine and 5-methylcytosine (to uracil and thymine ) forms the basis of bisulfite sequencing .
Cytosine deamination commonly occurs under physiological conditions and essentially is the deamination of cytosine. This process yields uracil as its product, which is not a base pair found within DNA. This process causes extensive DNA damage.
Hydrolytic deamination of the cytosine amine group then occurs, catalyzed by the proton transfer from the nearby glutamic acid residue, and the enzymatic structure is conserved by a proline residue. [10] Possible mechanism for C-to-U modification using Zinc complex with H-66, Cys-93, and Cys-96.
A mechanism of generating protein diversity is mRNA editing. The APOBEC family of proteins perform mRNA modifications by deaminating cytidine bases to uracil. The N-terminal domain of APOBEC-like proteins is the catalytic domain, while the C-terminal domain is a pseudocatalytic domain. More specifically, the catalytic domain is a zinc dependent ...