Lipoic acid is assembled on its cognate proteins (e.g. the E2 subunit of pyruvate dehydrogenase). An octanoyl moiety is transferred from the octanoyl-ACP of fatty acid synthetase to a specific lysine residue of the cognate protein followed by sulfur insertion at C6 and C8 of the octanoyl chain. The challenging chemistry of this last step is performed by the radical S-adenosylmethionine (SAM) enzyme lipoyl synthase (LipA). In this issue of the Biochemical Journal, Harmer et al. report the first crystal structure of a lipoyl synthase and demonstrate that it contains two [4Fe–4S] clusters, the canonical radical SAM cluster plus a second auxiliary cluster having an unprecedented serine ligand. The structure provides strong support for the model in which the auxiliary cluster donates the lipoate sulfur atoms.
Skip Nav Destination
Article navigation
November 2014
- Cover Image
- PDF Icon PDF LinkFront Matter
- PDF Icon PDF LinkTable of Contents
- PDF Icon PDF LinkEditorial Board
Commentary|
October 23 2014
The structure of lipoyl synthase, a remarkable enzyme that performs the last step of an extraordinary biosynthetic pathway
John E. Cronan
John E. Cronan
1
*Departments of Microbiology and Biochemistry, University of Illinois, Urbana, IL 61801, U.S.A.
1email j-cronan@life.uiuc.edu
Search for other works by this author on:
Biochem J (2014) 464 (1): e1–e3.
Article history
Received:
August 15 2014
Accepted:
August 18 2014
Connected Content
A commentary has been published:
Structures of lipoyl synthase reveal a compact active site for controlling sequential sulfur insertion reactions
Citation
John E. Cronan; The structure of lipoyl synthase, a remarkable enzyme that performs the last step of an extraordinary biosynthetic pathway. Biochem J 15 November 2014; 464 (1): e1–e3. doi: https://doi.org/10.1042/BJ20141061
Download citation file:
Sign in
Don't already have an account? Register
Sign in to your personal account
You could not be signed in. Please check your email address / username and password and try again.
Could not validate captcha. Please try again.