4NJI

Crystal Structure of QueE from Burkholderia multivorans in complex with AdoMet, 6-carboxy-5,6,7,8-tetrahydropterin, and Mg2+

Summary for 4NJI

• Entry DOI: 10.2210/pdb4nji/pdb
• Related: 4NJG 4NJH 4NJJ 4NJK
• Descriptor: 7-carboxy-7-deazaguanine synthase, IRON/SULFUR CLUSTER, S-ADENOSYLMETHIONINE, ... (8 entities in total)
• Functional Keywords: adomet radical enzyme, modified partial tim barrel-like structure, radical sam fold, radical adomet fold, synthase, lyase
• Biological source: Burkholderia multivorans
• Total number of polymer chains: 2
• Total formula weight: 52871.50

Authors

Dowling, D.P.,Bruender, N.A.,Young, A.P.,McCarty, R.M.,Bandarian, V.,Drennan, C.L. (deposition date: 2013-11-10, release date: 2013-12-25, Last modification date: 2023-09-20)

Primary citation

Dowling, D.P.,Bruender, N.A.,Young, A.P.,McCarty, R.M.,Bandarian, V.,Drennan, C.L.
Radical SAM enzyme QueE defines a new minimal core fold and metal-dependent mechanism.
Nat.Chem.Biol., 10:106-112, 2014

PubMed Abstract: 7-carboxy-7-deazaguanine synthase (QueE) catalyzes a key S-adenosyl-L-methionine (AdoMet)- and Mg(2+)-dependent radical-mediated ring contraction step, which is common to the biosynthetic pathways of all deazapurine-containing compounds. QueE is a member of the AdoMet radical superfamily, which employs the 5'-deoxyadenosyl radical from reductive cleavage of AdoMet to initiate chemistry. To provide a mechanistic rationale for this elaborate transformation, we present the crystal structure of a QueE along with structures of pre- and post-turnover states. We find that substrate binds perpendicular to the [4Fe-4S]-bound AdoMet, exposing its C6 hydrogen atom for abstraction and generating the binding site for Mg(2+), which coordinates directly to the substrate. The Burkholderia multivorans structure reported here varies from all other previously characterized members of the AdoMet radical superfamily in that it contains a hypermodified (β6/α3) protein core and an expanded cluster-binding motif, CX14CX2C.

PubMed: 24362703
DOI: 10.1038/nchembio.1426

Experimental method

X-RAY DIFFRACTION (2.197 Å)