1mnl
From Proteopedia
(New page: 200px<br /><applet load="1mnl" size="450" color="white" frame="true" align="right" spinBox="true" caption="1mnl" /> '''HIGH-RESOLUTION SOLUTION STRUCTURE OF A SWEE...) |
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'''HIGH-RESOLUTION SOLUTION STRUCTURE OF A SWEET PROTEIN SINGLE-CHAIN MONELLIN (SCM) DETERMINED BY NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY AND DYNAMICAL SIMULATED ANNEALING CALCULATIONS, 21 STRUCTURES'''<br /> | '''HIGH-RESOLUTION SOLUTION STRUCTURE OF A SWEET PROTEIN SINGLE-CHAIN MONELLIN (SCM) DETERMINED BY NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY AND DYNAMICAL SIMULATED ANNEALING CALCULATIONS, 21 STRUCTURES'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Single-chain monellin (SCM), which is an engineered 94-residue | + | Single-chain monellin (SCM), which is an engineered 94-residue polypeptide, has proven to be as sweet as native two-chain monellin. SCM is more stable than the native monellin for both heat and acidic environments. Data from gel filtration HPLC and NMR indicate that the SCM exists as a monomer in aqueous solution. The solution structure of SCM has been determined by nuclear magnetic resonance (NMR) spectroscopy and dynamical simulated annealing calculations. A stable alpha-helix spanning residues Phe11-Ile26 and an antiparallel beta-sheet formed by residues 2-5, 36-38, 41-47, 54-64, 69-75, and 83-88 have been identified. The sheet was well defined by backbone-backbone NOEs, and the corresponding beta-strands were further confirmed by hydrogen bond networks based on amide hydrogen exchange data. Strands beta2 and beta3 are connected by a small bulge comprising residues Ile38-Cys41. A total of 993 distance and 56 dihedral angle restraints were used for simulated annealing calculations. The final simulated annealing structures (<SA>k) converged well with a root-mean-square deviation (rmsd) between backbone atoms of 0.49 A for secondary structural regions and 0.70 A for backbone atoms excluding two loop regions. The average restraint energy-minimized (REM) structure exhibited root-mean-square deviations of 1.19 A for backbone atoms and 0.85 A for backbone atoms excluding two loop regions with respect to 20 <SA>k structures. The solution structure of SCM revealed that the long alpha-helix was folded into the concave side of a six-stranded antiparallel beta-sheet. The side chains of Tyr63 and Asp66 which are common to all sweet peptides showed an opposite orientation relative to H1 helix, and they were all solvent-exposed. Residues at the proposed dimeric interface in the X-ray structure were observed to be mostly solvent-exposed and demonstrated high degrees of flexibility. |
==About this Structure== | ==About this Structure== | ||
| - | 1MNL is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Dioscoreophyllum_cumminsii Dioscoreophyllum cumminsii]. Full crystallographic information is available from [http:// | + | 1MNL is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Dioscoreophyllum_cumminsii Dioscoreophyllum cumminsii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MNL OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Dioscoreophyllum cumminsii]] | [[Category: Dioscoreophyllum cumminsii]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Chang, H | + | [[Category: Chang, H J.]] |
| - | [[Category: Jo, J | + | [[Category: Jo, J M.]] |
| - | [[Category: Jung, J | + | [[Category: Jung, J W.]] |
| - | [[Category: Lee, J | + | [[Category: Lee, J H.]] |
| - | [[Category: Lee, S | + | [[Category: Lee, S Y.]] |
[[Category: Lee, W.]] | [[Category: Lee, W.]] | ||
[[Category: alpha/beta motif]] | [[Category: alpha/beta motif]] | ||
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[[Category: sweet receptor binding]] | [[Category: sweet receptor binding]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:57:01 2008'' |
Revision as of 11:57, 21 February 2008
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HIGH-RESOLUTION SOLUTION STRUCTURE OF A SWEET PROTEIN SINGLE-CHAIN MONELLIN (SCM) DETERMINED BY NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY AND DYNAMICAL SIMULATED ANNEALING CALCULATIONS, 21 STRUCTURES
Overview
Single-chain monellin (SCM), which is an engineered 94-residue polypeptide, has proven to be as sweet as native two-chain monellin. SCM is more stable than the native monellin for both heat and acidic environments. Data from gel filtration HPLC and NMR indicate that the SCM exists as a monomer in aqueous solution. The solution structure of SCM has been determined by nuclear magnetic resonance (NMR) spectroscopy and dynamical simulated annealing calculations. A stable alpha-helix spanning residues Phe11-Ile26 and an antiparallel beta-sheet formed by residues 2-5, 36-38, 41-47, 54-64, 69-75, and 83-88 have been identified. The sheet was well defined by backbone-backbone NOEs, and the corresponding beta-strands were further confirmed by hydrogen bond networks based on amide hydrogen exchange data. Strands beta2 and beta3 are connected by a small bulge comprising residues Ile38-Cys41. A total of 993 distance and 56 dihedral angle restraints were used for simulated annealing calculations. The final simulated annealing structures (<SA>k) converged well with a root-mean-square deviation (rmsd) between backbone atoms of 0.49 A for secondary structural regions and 0.70 A for backbone atoms excluding two loop regions. The average restraint energy-minimized (REM) structure exhibited root-mean-square deviations of 1.19 A for backbone atoms and 0.85 A for backbone atoms excluding two loop regions with respect to 20 <SA>k structures. The solution structure of SCM revealed that the long alpha-helix was folded into the concave side of a six-stranded antiparallel beta-sheet. The side chains of Tyr63 and Asp66 which are common to all sweet peptides showed an opposite orientation relative to H1 helix, and they were all solvent-exposed. Residues at the proposed dimeric interface in the X-ray structure were observed to be mostly solvent-exposed and demonstrated high degrees of flexibility.
About this Structure
1MNL is a Single protein structure of sequence from Dioscoreophyllum cumminsii. Full crystallographic information is available from OCA.
Reference
Solution structure of a sweet protein single-chain monellin determined by nuclear magnetic resonance and dynamical simulated annealing calculations., Lee SY, Lee JH, Chang HJ, Cho JM, Jung JW, Lee W, Biochemistry. 1999 Feb 23;38(8):2340-6. PMID:10029527
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