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. It is represented in all extant phyla, from prokaryotes to humans.

What are ABC type transporters?

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. It is represented in all extant phyla, from prokaryotes to humans.

Are ABC transporters primary?

ATP-binding cassette (ABC) transporters comprise the largest family of primary active transporters found in all kingdoms of life. They use the free energy of ATP hydrolysis for translocation of a broad variety of solutes.

What are ABC and SLC transporters?

Membrane Transporter Classification Membrane transporters can be also divided into three main classes; ABC transporters, P-type ATPases and the solute carrier family (SLC). ABC transporters are primary active transporters, which transport a wide range of substrates mainly to the outside of a cell membrane or organelle.

How many types of ABC transporters 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).

Are ABC transporters enzymes?

Unlike other enzymes that use ATP as an energy source, ABC transporters are notorious for having high levels of basal ATPase activity: they hydrolyze ATP also in the absence of their substrate.

What do ABC transporters do?

ATP-binding cassette (ABC) transporters are a large superfamily of membrane proteins with diverse functions (Holland et al. 2003). They convert the energy gained from ATP hydrolysis into trans-bilayer movement of substrates either into the cytoplasm (import) or out of the cytoplasm (export).

How many ABC transporters are there in humans?

49 ABC
The human genome carries 49 ABC genes, arranged in seven subfamilies, designated A to G (Figure ​1 and Table ​ 1). This diverse transporter family has members that play pivotal roles in many cellular processes.

What are ABC transporters that are found in bacterial membranes?

Primary transporters include the rotary motor ATPases (F-, A-, and V-ATPases), P-type ATPases and a large family of integral membrane proteins referred to as “ABC” (ATP binding cassette) transporters.

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.

Is the sodium potassium pump an ABC transporter?

ABC transporters use ATP to transport a variety of different substrates across cell membranes, most commonly out of the cell. Both the Sodium-potassium pump and ABC transporters are examples of primary active transport.

What are the two general types of transporters?

There are two main types of active transport:

  • Primary (direct) active transport – Involves the direct use of metabolic energy (e.g. ATP hydrolysis) to mediate transport.
  • Secondary (indirect) active transport – Involves coupling the molecule with another moving along an electrochemical gradient.

Are ABC transporters secondary active transport?

Surprisingly, this truncated protein mediates a proton-ethidium symport reaction without the requirement for ATP. In other words, it functions as a secondary-active multidrug uptake system.