From Proteopedia

proteopedia linkproteopedia link

Revision as of 04:22, 21 March 2010 (edit) Anthony Daniele (Talk | contribs) (→Reaction of CAT III) ← Previous diff		Revision as of 04:23, 21 March 2010 (edit) (undo) Anthony Daniele (Talk | contribs) (→Reaction of CAT III) Next diff →
Line 17:		Line 17:
	[[Image:Picture2.jpg|500x400 px|center]]		[[Image:Picture2.jpg|500x400 px|center]]
-	In the first step of the reaction, Histidine-156 abstracts a proton from the 3-hydroxyl of chloramphenicol, causing a nucleophilic attack from the deprotonated oxygen onto the thioester bond of the acetyl-CoA. The 3-acetylchloramphenicol intermediate then rearranges, non-enzymatically, to a 1-acetylchloramphenicol intermediate. CAT III then causes another acetylation of the now regenerated 3-hydroxyl and 1,3-diacetylchloramphenicol is produced.	+	In the first step of the reaction, Histidine-156 abstracts a proton from the 3-hydroxyl of chloramphenicol, promoting a nucleophilic attack from the deprotonated oxygen onto the thioester bond of the acetyl-CoA. The 3-acetylchloramphenicol intermediate then rearranges, non-enzymatically, to a 1-acetylchloramphenicol intermediate. CAT III then causes another acetylation of the now regenerated 3-hydroxyl and 1,3-diacetylchloramphenicol is produced.

---

Revision as of 04:23, 21 March 2010

Anthony Daniele

Chloramphenicol Acetyltransferase Type III

Chloramphenicol acetyltransferase type III (CAT III) is an enzyme which catalyzes the transfer of acetyl from acetyl-CoA to hydroxyl groups of chloramphenicol. CAT III is a trimeric protein

Introduction

Reaction of CAT III

---

In the first step of the reaction, Histidine-156 abstracts a proton from the 3-hydroxyl of chloramphenicol, promoting a nucleophilic attack from the deprotonated oxygen onto the thioester bond of the acetyl-CoA. The 3-acetylchloramphenicol intermediate then rearranges, non-enzymatically, to a 1-acetylchloramphenicol intermediate. CAT III then causes another acetylation of the now regenerated 3-hydroxyl and 1,3-diacetylchloramphenicol is produced.

Please do NOT make changes to this Sandbox until after April 23, 2010. Sandboxes 151-200 are reserved until then for use by the Chemistry 307 class at UNBC taught by Prof. Andrea Gorrell.