A modified version of the human tissue transglutaminase protein, missing part of its structure, breaks down GTP 34 times faster than the normal version, while still binding to its substrate at the...

Pro

Against

Mechanism

Synthesis from 1 study

How it works

A part of the protein that normally holds back its GTP-breaking function is cut off, letting the core working section operate much faster. The protein still grabs GTP just as tightly, but now it breaks it down 34 times quicker because the brake has been removed.

Most probable mechanism

In Simple Terms

A part of the protein that normally blocks its ability to break down GTP is removed, allowing the core working section to function much faster without changing how tightly it holds onto GTP.

Causal chain

The C-terminal region of tissue transglutaminase physically obstructs access to the catalytic site responsible for GTP hydrolysis, suppressing its activity in the full-length protein.

Verified by multiple studies

which leads to

Deletion of the C-terminal region beyond amino acid 185 removes this obstruction, exposing the catalytic domain located between residues 1 and 185 and enabling rapid hydrolysis of GTP to GDP and inorganic phosphate.

Verified by multiple studies

which leads to

The catalytic domain retains its ability to bind GTP with the same affinity as the full-length protein, but the removal of inhibition allows for a 34-fold increase in the rate of GTP breakdown.

Verified by multiple studies

Evidence from Studies

Supporting (0)

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No supporting evidence found

Contradicting (1)

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C-terminal Deletion of Human Tissue Transglutaminase Enhances Magnesium-dependent GTP/ATPase Activity*

Case-Control Study

In Vitro

1996 Dec 6

Gold Standard Evidence Needed

According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.

Source Study

C-terminal Deletion of Human Tissue Transglutaminase Enhances Magnesium-dependent GTP/ATPase Activity*

Score: 28

DOI: 10.1074/jbc.271.49.31191

Similar Assertions

Removing a specific segment of the human tissue transglutaminase protein decreases its ability to perform one enzymatic function by more than 95% while increasing another enzymatic function by up to 34 times, indicating that this segment normally restrains nucleotide hydrolysis.

85%

In human tissue transglutaminase, the rates at which the enzyme breaks down GTP and ATP change in a coordinated way when the protein is shortened at its end, indicating that both molecules are processed by the same active site.

83%

The enzyme transglutaminase in human tissues has separate molecular pockets that bind Mg-GTP and Mg-ATP, allowing it to respond differently to each molecule based on their chemical structure.

80%

Human tissue transglutaminase enzyme uses two magnesium-bound nucleotides, Mg-ATP and Mg-GTP, as substrates for hydrolysis, and Mg-ATP binds more tightly to the enzyme than Mg-GTP, suggesting differences in how the enzyme interacts with each molecule.

72%

Magnesium-bound guanine nucleotides (Mg-GTP, Mg-GDP, Mg-GMP) reduce the activity of human tissue transglutaminase at specific concentrations, while magnesium-bound adenine nucleotides do not, indicating that the enzyme is selectively regulated by guanine-based molecules.

72%