What is an ABC transporter including defining the ABC part?
The ATP-binding cassette transporters (ABC transporters) are a transport system superfamily that is one of the largest and possibly one of the oldest gene families. Some homologous ATPases function in non-transport-related processes such as translation of RNA and DNA repair.
What do ABC transporters carry?
ABC transporters are transmembrane proteins that utilize the energy of adenosine triphosphate (ATP) hydrolysis to carry out certain biological processes including translocation of various substrates across membranes and non-transport-related processes such as translation of RNA and DNA repair.
Are ABC transporters active or passive?
ABC transporters are primary active transporters, which transport a wide range of substrates mainly to the outside of a cell membrane or organelle.
What are the types of ABC transporters?
The canonical ABC transporter is organized in four functional units or domains, two NBDs (NBD1, NBD2) and two TMDs (TMD1, TMD2). In bacteria, the four domains can be a combination of individual, pairwise identical subunits, or a combination of fused NBDs and/or TMDs [12].
Which one of the following is an ABC transporter?
Correct Option: A. The nine multidrug resistance proteins (MRPs) represent the major part of the 12 members of the MRP/CFTR subfamily belonging to the 48 human ATP-binding cassette (ABC) transporters.
Which of the following is an example of an ABC transporter?
ATP-binding cassette (ABC) transporters are an example of ATP-dependent pumps. ABC transporters are ubiquitous membrane-bound proteins, present in all prokaryotes, as well as plants, fungi, yeast and animals. These pumps can move substrates in (influx) or out (efflux) of cells.
What distinguishes P-type transporters from ABC transporters?
What distinguishes P-type transporters from ABC transporters? ATP hydrolysis by P-type transporters results in a phosphorylated intermediate while ATP hydrolysis causes ABC transporters to convert from an outward facing transporter to an inward facing transporter.
How many ABC transporter are there?
There are 48 ABC transporters in humans [8,9] and many of these have been shown to be responsible for or involved in disease states, including cystic fibrosis, Tangier disease, adrenoleukodystrophy, and cancer (see below).
What is the architecture of ABCABC transporter?
ABC transporters have a characteristic architecture, which consists minimally of four domains ( Fig. 1a ): two transmembrane domains (TMDs) embedded in the membrane bilayer and two ABCs (also designated as the nucleotide binding domains (NBDs)) located in the cytoplasm.
What is the function of the ABC domain in ABC transporters?
The highly conserved ABC domains of ABC transporters provide the nucleotide-dependent engine that drives transport. By contrast, the transmembrane domains that create the translocation pathway are more variable.
What are the substrates transported by the ABC transporter?
The substrates that can be transported include ions, amino acids, peptides, sugars, and other molecules that are mostly hydrophilic. The membrane-spanning region of the ABC transporter protects hydrophilic substrates from the lipids of the membrane bilayer thus providing a pathway across the cell membrane.
What is the general mechanism for the transport cycle of ABCs?
The general mechanism for the transport cycle of ABC transporters has not been fully elucidated but substantial structural and biochemical data has accumulated to support a model in which ATP binding and hydrolysis is coupled to conformational changes in the transporter.