ABC similarity of the gene structure and

ABC transporter is a kind of proteins
from the largest family of proteins. Also called ATP-binding cassette. It
constructs of four domains, tow transmembrane domain (TMD) and two nucleotides
binding domain (NBD).If the four domains present in one protein chain, it
considered “full transporter” and if the four domains separate in two
protein chains, it considered “half transporter”. This transporter
present in all living organisms. It consisting of seven subfamilies classified
based on similarity of the gene structure and order of domains of the
transporter in NBDs and TMDs. The subfamilies have arranged from A to G, each
part of these families have many members, 48 members have known until now. It
has an important role in transporting reactions such as import and export
micronutrients from the cell, this kind found in prokaryotes. In eukaryotes, it
plays a major role in pumping the molecules out of the cell.

Mechanism and function:

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ABC transporter uses the energy that
released from hydrolysis of ATP to drive the reactions. When the NBDs opens,
the substrate enters the cavity that formed between the two domains, this
causes NBDs to close. Two ATP molecules bind to each NBDs and hydrolyzed to
produce energy that causes in conformational change lead to open the other side
of the transporter and pump the substrate out of the cell. In this way, the
transporter work to achieve many roles involves protecting against xenobiotics,
oxidative stress, rid of toxin from the cell, lipid metabolism, absorption, and
secretion.

ATP binding cassette subfamily B member 1(ABCB1)

The human multidrug transporter, it also
called P-glycoprotein. It constructs of both: full transport and half
transport. It expressed in many tissues in the body such as adrenal, kidney,
endothelial cell of the blood-brain barrier, hepatocyte, and brush border of
the intestine. ABCB1 has an important role in the protection of cell from toxic
compounds. It recognizes and effluxes molecules that their molecular weight
from 250 to 4000. For example, it can efflux xenobiotics, some dietary
compounds, a steroid hormone, cholesterol, lipid, phospholipid, and cytokines.
It also contributes to cellular homeostasis.