What is a P-loop motif?

The phosphate-binding loop (P-loop) is a conserved sequence motif found in the superfamily of P-loop nucleoside triphosphate hydrolases (P-loop NTPases)1. The P-loop, also known as the Walker A motif, has the consensus sequence GxxxxGK(S/T) and contributes to the binding of nucleotides2,3.

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What is the function of the P-loop motif in the proteins that contain this sequence of amino acids?

Of the two motifs, the A motif is the main “P-loop” responsible for binding phosphate, while the B motif is a much less conserved downstream region. The P-loop is best known for its presence in ATP- and GTP-binding proteins, and is also found in a variety of proteins with phosphorylated substrates.

What are P-loop NTPase superfamily?

Members of the P-loop NTPase superfamily are characterized by presence of a highly conserved sequence pattern GxxxxGKS/T, known as Walker A motif. This motif adopts an archetypal P-loop conformation which allows accommodation of the triphosphate moiety of a bound nucleotide.

What is P-loop in kinase?

The P-loop, which normally exists in an extended conformation, is a stretch of nine aminoacids that in MAP4K4 is delimited by residues V31 and V39. MAP4K4, also called HGK or ZC1, is a serine/threonine protein kinase that belongs to the mammalian STE20/MAP4K family.

What are protein motifs and domains?

A motif in protein structure refers to a chain-like biological structure made up of connectivity between secondary structural elements while a domain in protein structure refers to an independent folding unit of the three-dimensional protein structure.

What type of enzyme is Atpase?

ATPases are a group of enzymes that catalyze the hydrolysis of a phosphate bond in adenosine triphosphate (ATP) to form adenosine diphosphate (ADP). They harness the energy released from the breakdown of the phosphate bond and utilize it to perform other cellular reactions.

What is a motif vs domain?

What is motif in protein structure?

A motif is a short conserved sequence pattern associated with distinct functions of a protein or DNA. It is often associated with a distinct structural site performing a particular function. A typical motif, such as a Zn-finger motif, is ten to twenty amino acids long.

What is the difference between ATP and ATPase?

The enzyme which catalyzes the below-mentioned reaction is called an ATP Synthase. So, the key difference between ATPase and ATP Synthase is, ATPase is the enzyme that breaks down ATP molecules while the ATP Synthase involves in ATP production.

What activates ATPase?

tabacum BY2 cell culture weak organic acids, which are expected to permeate the membrane as a protonated form and dissociate once inside, resulting in cytosol acidification. This is expected to activate the plasma membrane H+-ATPase and so remove the proton excess out off the cell.

What are examples of motifs?

Examples of Motif in Narrative Writing

A repeated reference or visual of shattered glass (something in life is about to break)
Recurring dishonest characters (to cue up the discovery of an unfaithful spouse)
A character who constantly misplaces things (as the loss of someone or something significant is on the horizon)

Are all domains motifs?

Domains are normally longer than motifs. A domain consists of more than 40 residues and up to 700 residues, with an average length of 100 residues. A domain may or may not include motifs within its boundaries. Examples of domains include transmembrane domains and ligand-binding domains.

What is the difference between a-loop and Walker B motif?

The A-loop ( aromatic residue interacting with the adenine ring of ATP) refers to conserved aromatic amino acids, essential for ATP-binding, found in about 25 amino acids upstream of the Walker A motif in a subset of P-loop proteins. Walker B motif is a motif in most P-loop proteins situated well downstream of the A-motif.

Does Walker motif a-binding cause structural changes in DNA binding?

Walker motif A-binding has been shown to cause structural changes in the bound nucleotide, along the line of the induced fit model of enzyme binding.

What is the P-loop motif in bacteriophage lambda?

During the assembly of many viruses, a powerful ATP-driven motor translocates DNA into a preformed procapsid. A Walker-A “P-loop” motif is proposed to coordinate ATP binding and hydrolysis with DNA translocation. We use genetic, biochemical, and biophysical techniques to survey the roles of P-loop residues in bacteriophage lambda motor function.