Text: THIS STRUCTURE WAS DETERMINED USING DIPOLAR COUPLING MEASURED IN LIQUID CRYSTAL MEDIA. IN ADDITION, WE ALSO MEASURED HYDROGEN BONDS DIRECTLY AND USED THEM IN STRUCTURE CALCULATIONS.
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試料調製
詳細
内容: ~0.7 MM PROTEIN MAP30 (15N/13C) ENRICHED.
試料状態
イオン強度: 10 mM NAPI / pH: 5.5 / 圧: 1 atm / 温度: 313.00 K
結晶化
*PLUS
手法: other / 詳細: NMR
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NMR測定
NMRスペクトロメーター
タイプ
製造業者
モデル
磁場強度 (MHz)
Spectrometer-ID
Bruker DMX
Bruker
DMX
500
1
Bruker DMX
Bruker
DMX
600
2
Bruker DMX
Bruker
DMX
750
3
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解析
NMR software
名称
バージョン
開発者
分類
MODIFIED X-PLOR
3.5
BRUNGER
精密化
MODIFIED X-PLOR
3.5
BRUNGER
構造決定
精密化
手法: simulated annealing / ソフトェア番号: 1 詳細: WE CALCULATED THE STRUCTURE OF MAP30 USING SIMULATED ANNEALING IN TORSION ANGLE SPACE STARTING FROM AN EXTENDED STRAND, FOLLOWED BY SIMULATED ANEALING IN CARTESIAN SPACE USING A MODIFIED ...詳細: WE CALCULATED THE STRUCTURE OF MAP30 USING SIMULATED ANNEALING IN TORSION ANGLE SPACE STARTING FROM AN EXTENDED STRAND, FOLLOWED BY SIMULATED ANEALING IN CARTESIAN SPACE USING A MODIFIED XPLOR 3.5, CONTAINING PSEUDOPOTENTIALS FOR RESIDUAL DIPOLAR COUPLING AND A CONFORMATIONAL DATABASE. HYDROGEN BOND CONSTRAINTS, TWO FOR EACH HYDROGEN BOND (NH-O = 1.5-2.8 A AND N-O = 2.4-3.5 A), WERE DERIVED FROM NH EXCHANGE EXPERIMENTS, BACKBONE NOE PATTERNS, BACKBONE CA/CB CHEMICAL SHIFTS AND DIRECT MEASUREMENTS OF 3HJNC CONNECTIVITY ACROSS HYDROGEN BONDS, AND APPLIED IN THE LATER STAGE OF THE STRUCTURE CALCULATION. PHI AND PSI ANGLES WERE DERIVED FROM THREE-BOND 3JHNHA COUPLING CONSTANTS, MEASURED WITH THE 3D HNHA EXPERIMENT AND A DATABASE ANALYSIS OF BACKBONE (1H, 15N, 13CA, 13CB AND C) CHEMICAL SHIFTS, USING THE PROGRAM TALOS. THE PHI DIHEDRAL ANGLE WAS RESTRAINED TO -60 DEGREES PLUS-MINUS 30 DEGREES IF JHNHA < 5.5 HZ OR TO 110 DEGREES PLUS-MINUS 50 DEGREES IF JHNHA >8.0 HZ. CHI 1 DIHEDRAL ANGLES AND STEREOSPECIFIC ASSIGNMENTS OF BETA- METHYLENE PROTONS WERE DERIVED FROM JHNHB AND JHAHB SCALAR COUPLING CONSTANTS OBTAINED FROM 3D HNHB AND HACAHB-COSY EXPERIMENTS. TIGHT TURNS CLEARLY IDENTIFIED BY NOE PATTERNS AND J-COUPLING CONSTANTS, PHI AND PSI ANGLES WERE RESTRAINED TO THEIR STANDARD VALUES WITH PLUS-MINUS 30 DEGREES ERROR RANGE. FOR RESIDUES HAVING INTENSE INTRARESIDUE HN-HA NOES WITH POSITIVE PHI ANGLES SUGGESTED BY THE PROGRAM TALOS, PHI WAS RESTRAINED TO 40 DEGREES PLUS-MINUS 15 DEGREES. ELECTROSTATIC SURFACES WERE CALCULATED USING GRASP. MOLECULAR MODELS WERE GENERATED WITH QUANTA (MSI), INSIGHT (MSI) AND MOLSCRIPT.