ATP-binding cassette family
Encyclopedia
The ATP-binding cassette (ABC) family is a group of protein
s which bind and hydrolyse ATP
in order to transport substances across cellular membranes. They are prevalent in bacteria
but are also in humans, and responsible for a diverse range of genetic diseases from Stargardt disease to Cystic Fibrosis
.
binding domains (areas where ATP
binds to the protein and are hydrolysed to ADP
) and two transmembrane domains (parts of the protein which span the membrane through which the substrate
that's to be transported passes, the substrate translocation pathway).
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
s which bind and hydrolyse ATP
Adenosine triphosphate
Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...
in order to transport substances across cellular membranes. They are prevalent in bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
but are also in humans, and responsible for a diverse range of genetic diseases from Stargardt disease to Cystic Fibrosis
Cystic fibrosis
Cystic fibrosis is a recessive genetic disease affecting most critically the lungs, and also the pancreas, liver, and intestine...
.
Structure
ABC proteins have two nucleotideNucleotide
Nucleotides are molecules that, when joined together, make up the structural units of RNA and DNA. In addition, nucleotides participate in cellular signaling , and are incorporated into important cofactors of enzymatic reactions...
binding domains (areas where ATP
Adenosine triphosphate
Adenosine-5'-triphosphate is a multifunctional nucleoside triphosphate used in cells as a coenzyme. It is often called the "molecular unit of currency" of intracellular energy transfer. ATP transports chemical energy within cells for metabolism...
binds to the protein and are hydrolysed to ADP
Adenosine diphosphate
Adenosine diphosphate, abbreviated ADP, is a nucleoside diphosphate. It is an ester of pyrophosphoric acid with the nucleoside adenosine. ADP consists of the pyrophosphate group, the pentose sugar ribose, and the nucleobase adenine....
) and two transmembrane domains (parts of the protein which span the membrane through which the substrate
Substrate (biochemistry)
In biochemistry, a substrate is a molecule upon which an enzyme acts. Enzymes catalyze chemical reactions involving the substrate. In the case of a single substrate, the substrate binds with the enzyme active site, and an enzyme-substrate complex is formed. The substrate is transformed into one or...
that's to be transported passes, the substrate translocation pathway).