Read the following paragraph and answer the questions below

Read the following paragraph and answer the questions below.

Anthranilate phosphoribosyltransferase (AnPRT) is essential for the biosynthesis of tryptophan in Mycobacterium tuberculosis (Mtb). This enzyme catalyzes the second committed step in tryptophan biosynthesis, the Mg²⁺-dependent reaction between 5-phosphoribosyl-1-pyrophosphate (PRPP) and anthranilate. The roles of residues predicted to be involved in anthranilate binding have been tested by the analysis of six Mtb-AnPRT variant proteins. Kinetic analysis showed that five of six variants were active and identified the conserved residue R193 as being crucial for both anthranilate binding and catalytic function. Crystal structures of these Mtb-AnPRT variants reveal the ability of anthranilate to bind in three sites along an extended anthranilate tunnel and expose the role of the mobile 26 loop in facilitating the enzyme’s sequential reaction mechanism. The 26 loop moves sequentially between a “folded” conformation, partially occluding the anthranilate tunnel, via an “open” position to a “closed” conformation, which supports PRPP binding and allows anthranilate access via the tunnel to the active site. The return of the 26 loop to the “folded” conformation completes the catalytic cycle, concordantly allowing the active site to eject the product PRA and rebind anthranilate at the opening of the anthranilate tunnel for subsequent reactions. Multiple anthranilate molecules blocking the anthranilate tunnel prevent the 26 loop from undergoing the conformational changes required for catalysis, thus accounting for the unusual substrate inhibition of this enzyme.

QUESTIONS:

1) Why is this research significant or important?

2) What technique did they use in the study?

3) What did they study?

4) What were their results?

5) What did they conclude from the results?

Solution

Ques-1) Why is this research significant or important?

This research is important to know the \"enzyme kinetic activities (Anthranilate phosphoribosyltransferase (AnPRT))\" tryptophan biosynthesis in Mycobacterium tuberculosis, a devastating bacterial species that causes tuberculosis in humans. This research is significant to promote synthesis of new antibiotics & chemotherapeutic molecules and their structure activity relationships with this enzyme kinetics to target \"tryptophan biosynthesis\" in Mycobacterium tuberculosis

Ques-2) What technique did they use in the study?

Kinetic analysis of enzyme mechanisms involving substrate binding with PRPP and unraveling kinetics of enzymatic variants with R193 as being crucial for both anthranilate binding and catalytic function using \"spectrophotometric analysis\" (UV-visible spectroscopy). Crystal structures of these Mtb-AnPRT variants are essential to know the conformation changes (open/folded) to know the role of the mobile 26 loop in facilitating the enzyme’s sequential reaction mechanism & these mechanisms are analyzed by \"tunnel analysis\"

Ques-3) What did they study?

Crystal structures of these Mtb-AnPRT variants are essential to know the conformation changes (open/folded) to know the role of the mobile 26 loop in facilitating the enzyme’s sequential reaction mechanism. The roles of Anthranilate phosphoribosyltransferase (AnPRT) & PRPP residues predicted to be involved in anthranilate binding