Question

Explain Clearly Please!

1.Glycine residues on the N-termini of proteins can be myristoylated (C₁₄) by myristoyl-CoA. What biological purpose does this serve? Why does myristoylation drive the biology you just proposed?

Answer 1

Myristoylation is a lipidation modification where a myristoyl group, derived from myristic acid, is covalently attached by an amide bond to the alpha-amino group of an N-terminal glycine residue.

see the picture

myristie acid Met,-Gly, AA-AA,-AA, +COA-SH+ATP acyl-CoA synthetase methionyl aminop myristoyl-CoA Gly AA, AA AA AA myristoyl-CoA: protein N-myristoyltransterase (NMT) myristoylpeptide o myeistoylated protein protein-protein localisation

what is the purpose of myristoylated & why --The  post-translational protein modification which corresponds to the irreversible covalent linkage of a 14-carbon saturated fatty acid, the myristic acid, to the N-terminal glycine of an eukaryotic or viral protein.It is catalyzed by enzyme NMT ie N-Myristoyltransferase.

Myristoylation can occur during both co-translational protein synthesis and post-translationally, confers lipophilicity to protein molecules, and controls protein functions.

The myristoyl moiety can perform one or a combination of different roles in the cell:

• promote reversible membrane binding which, in conjunction with other interactions, localises a protein to a membrane,

• form an integral part of the protein tertiary structure to stabilise the conformation,

• form part of a protein–protein interaction site.

NMT1 is essential for growth and development, during which rapid cellular proliferation is required, in a variety of organisms. NMT1 is also reported to be elevated in many cancerous states, which also involve rapid cellular growth, albeit in an unwanted and uncontrolled manner. The delineation of myristoylation-dependent cellular functions is still in a state of infancy, and many of the roles of the myristoylated proteins remain to be established. For example, NMT1 plays a role in the development of cells of the leukocytic lineage, a phase of rapid growth and development.