4R0M

Structure of McyG A-PCP complexed with phenylalanyl-adenylate

Summary for 4R0M

• Entry DOI: 10.2210/pdb4r0m/pdb
• Descriptor: McyG protein, ADENOSINE-5'-[PHENYLALANINYL-PHOSPHATE] (3 entities in total)
• Functional Keywords: phenylalanyl-amp, adenylation domain, acetyl-coa synthetase-like domain, acyl carrier protein-like domain, peptidyl carrier protein like domain, phenylalanyl-amp binding, ligase
• Biological source: Microcystis aeruginosa PCC 7806
• Total number of polymer chains: 2
• Total formula weight: 147231.96

Authors

Tan, X.F.,Dai, Y.N.,Zhou, K.,Jiang, Y.L.,Ren, Y.M.,Chen, Y.X.,Zhou, C.Z. (deposition date: 2014-08-01, release date: 2015-04-15, Last modification date: 2024-11-06)

Primary citation

Tan, X.F.,Dai, Y.N.,Zhou, K.,Jiang, Y.L.,Ren, Y.M.,Chen, Y.,Zhou, C.Z.
Structure of the adenylation-peptidyl carrier protein didomain of the Microcystis aeruginosa microcystin synthetase McyG.
Acta Crystallogr.,Sect.D, 71:873-881, 2015

PubMed Abstract: Microcystins, which are the most common cause of hepatotoxicity associated with cyanobacterial water blooms, are assembled in vivo on a large multienzyme complex via a mixed nonribosomal peptide synthetase/polyketide synthetase (NRPS/PKS). The biosynthesis of microcystin in Microcystis aeruginosa PCC 7806 starts with the enzyme McyG, which contains an adenylation-peptidyl carrier protein (A-PCP) didomain for loading the starter unit to assemble the side chain of an Adda residue. However, the catalytic mechanism remains unclear. Here, the 2.45 Å resolution crystal structure of the McyG A-PCP didomain complexed with the catalytic intermediate L-phenylalanyl-adenylate (L-Phe-AMP) is reported. Each asymmetric unit contains two protein molecules, one of which consists of the A-PCP didomain and the other of which comprises only the A domain. Structural analyses suggest that Val227 is likely to be critical for the selection of hydrophobic substrates. Moreover, two distinct interfaces demonstrating variable crosstalk between the PCP domain and the A domain were observed. A catalytic cycle for the adenylation and peptide transfer of the A-PCP didomain is proposed.

PubMed: 25849398
DOI: 10.1107/S1399004715001716

Experimental method

X-RAY DIFFRACTION (2.45 Å)