1NQ4

Solution Structure of Oxytetracycline Acyl Carrier Protein

Summary for 1NQ4

• Entry DOI: 10.2210/pdb1nq4/pdb
• NMR Information: BMRB: 5664
• Descriptor: Oxytetracycline polyketide synthase acyl carrier protein (1 entity in total)
• Functional Keywords: solution structure, oxytetracycline, polyketide synthase, dynamics, acp, biosynthetic protein
• Biological source: Streptomyces rimosus
• Total number of polymer chains: 1
• Total formula weight: 9922.99

Authors

Findlow, S.C.,Winsor, C.,Simpson, T.J.,Crosby, J.,Crump, M.P. (deposition date: 2003-01-21, release date: 2003-11-04, Last modification date: 2024-05-22)

Primary citation

Findlow, S.C.,Winsor, C.,Simpson, T.J.,Crosby, J.,Crump, M.P.
Solution structure and dynamics of oxytetracycline polyketide synthase acyl carrier protein from Streptomyces rimosus
Biochemistry, 42:8423-8433, 2003

PubMed Abstract: Type II polyketide synthases (PKSs) utilize a dedicated and essential acyl carrier protein (ACP) in the biosynthesis of a specific polyketide product. As part of our ongoing studies into the mechanisms and control of polyketide biosynthesis, we report the second structure of a polyketide synthase ACP. In this work, multidimensional, heteronuclear NMR was employed to investigate the structure and dynamics of the ACP involved in the biosynthesis of the commonly prescribed polyketide antibiotic, oxytetracycline (otc). An ensemble of 28 structures of the 95 amino acid otc ACP (9916Da) was computed by simulated annealing with the inclusion of 1132 experimental restraints. Atomic RMSDs about the mean structure for all 28 models is 0.66 A for backbone atoms, 1.15 A for all heavy atoms (both values calculated for the folded part of the protein (residues 3-80)), and 0.41 A for backbone atoms within secondary structure. Otc ACP adopts the typical right-handed, four-helix fold of currently known ACPs but with the addition of a 13-residue flexible C-terminus. A comparison of the global folds of all structurally characterized ACPs is described, illustrating that PKS ACPs show clear differences as well as similarities to FAS ACPs. (15)N relaxation experiments for the protein backbone also reveal that the long loop between helices I and II is flexible and helix II, a proposed site of protein-protein interactions, shows conformational exchange. The helices of the ACP form a rigid scaffold for the protein, but these are interspersed with an unusual proportion of flexible linker regions.

PubMed: 12859187
DOI: 10.1021/bi0342259

Experimental method

SOLUTION NMR