dNMP stands for deoxyribonucleoside monophosphate, which is a fundamental building block of DNA. It's essentially a deoxynucleotide with a single phosphate group.
Here's a breakdown:
- Deoxyribonucleoside: This consists of a deoxyribose sugar molecule attached to a nitrogenous base (adenine, guanine, cytosine, or thymine).
- Monophosphate: This refers to a single phosphate group (PO₄³⁻) attached to the deoxyribose sugar.
During DNA synthesis, individual dNMPs are added to a growing DNA strand. The incoming dNTP (deoxyribonucleoside triphosphate, which has three phosphate groups) is used, and two phosphate groups are cleaved off (as pyrophosphate), providing the energy for the reaction and leaving a dNMP incorporated into the DNA. The specific dNMP added is determined by the complementary base on the template DNA strand.
Here's a visual representation of the process, adapted from the provided reference:
- (5′-DNA-polymer-3′-OH): This represents the growing DNA chain with a free 3' hydroxyl group.
- dNTP: An incoming deoxyribonucleoside triphosphate molecule. The specific base (A, T, C, or G) will determine which dNMP is added to the chain.
- dNMP addition: The dNMP is added to the 3' end of the growing chain, forming a phosphodiester bond.
- Pyrophosphate (PPi): Two phosphate groups are released as inorganic pyrophosphate.
Essentially, dNMPs are the incorporated, single-phosphate versions of dNTPs that make up the DNA polymer.
