Automated resonance assignment with FLYA (EMBO 2013): Difference between revisions
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We want to determine the resonance assignments and the structure of a protein. | We want to determine the resonance assignments and the structure of a protein using the program CYANA. | ||
== Experimental input data == | == Experimental input data == | ||
The protein sequence is stored in the file 'demo.seq'. | The protein sequence is stored in three-letter code in the file 'demo.seq'. | ||
The following spectra have been measured: | The following spectra have been measured: | ||
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* HC(CO)NH, called 'HC_CO_NH' in FLYA | * HC(CO)NH, called 'HC_CO_NH' in FLYA | ||
Peak lists that have been prepared by automatic peak picking with the program NMRView are stored in files ''XXX''.peaks, where ''XXX'' denotes the FLYA spectrum type. | Peak lists in XEASY format that have been prepared by automatic peak picking with the program NMRView are stored in files ''XXX''.peaks, where ''XXX'' denotes the FLYA spectrum type. | ||
Each peak list starts with a header that defines the experiment type and the order of dimensions. For instance, for HNCA.peaks: | Each peak list starts with a header that defines the experiment type and the order of dimensions. For instance, for HNCA.peaks: | ||
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7 6.475 54.017 98.159 1 U 2.547E+01 0.000E+00 e 0 0 0 0 | 7 6.475 54.017 98.159 1 U 2.547E+01 0.000E+00 e 0 0 0 0 | ||
The first line specifies the number of dimensions (3 in this case). The '#SPECTRUM' lines gives the experiment type (HNCA, which refers to the corresponding experiment definition in the CYANA library), followed by an identifier for each dimension of the peak list (HN C N) that specifies which chemical shift is stored in the corresponding | The first line specifies the number of dimensions (3 in this case). The '#SPECTRUM' lines gives the experiment type (HNCA, which refers to the corresponding experiment definition in the CYANA library), followed by an identifier for each dimension of the peak list (HN C N) that specifies which chemical shift is stored in the corresponding dimension of the peak list. These labels must match those in the corresponding experiment definition in the general CYANA library (see below). After the '#SPECTRUM' line follows one line for every peak. For example, the first peak in the 'HNCA.peaks' list has | ||
* Peak number 5 | * Peak number 5 | ||
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The other data are irrelevant for automated chemical shift assignment with FLYA. In particular, the peak volume or intensity (2.769E+02) is ''not'' used by the algorithm. | The other data are irrelevant for automated chemical shift assignment with FLYA. In particular, the peak volume or intensity (2.769E+02) is ''not'' used by the algorithm. | ||
== FLYA | == FLYA initialization script == | ||
The CYANA commands to run the automated assignment calculation are stored in two CYANA scripts or "macros". | The CYANA commands to run the automated assignment calculation are stored in two CYANA scripts or "macros". | ||
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The first line corresponds to the '#SPECTRUM' line in the peak list. It specifies the experiment name and a label for the atoms that are detected in each dimension of the spectrum. The number of labels defines the dimensionality of the experiment (3 in case of HNCA). | The first line corresponds to the '#SPECTRUM' line in the peak list. It specifies the experiment name and a label for the atoms that are detected in each dimension of the spectrum. The number of labels defines the dimensionality of the experiment (3 in case of HNCA). | ||
Each line below defines a (formal) magnetization transfer pathway that gives rise to an expected peak. | Each line below defines a (formal) magnetization transfer pathway that gives rise to an expected peak. Here |
Revision as of 22:19, 21 July 2013
We want to determine the resonance assignments and the structure of a protein using the program CYANA.
Experimental input data
The protein sequence is stored in three-letter code in the file 'demo.seq'.
The following spectra have been measured:
- [1H,13C]-HSQC, called 'C13H1' in FLYA
- [1H,15N]-HSQC, called 'N15H1' in FLYA
- HNCA
- HN(CO)CA, called 'HN_CO_CA' in FLYA
- HNCO
- HN(CA)CO, called 'HN_CA_CO' in FLYA
- CBCANH
- CBCACONH
- HBHACONH
- HCCH-TOCSY, called 'HCCH24' in FLYA
- HCCH-COSY, called 'HCCH7' in FLYA
- C(CO)NH, called 'C_CO_NH' in FLYA
- HC(CO)NH, called 'HC_CO_NH' in FLYA
Peak lists in XEASY format that have been prepared by automatic peak picking with the program NMRView are stored in files XXX.peaks, where XXX denotes the FLYA spectrum type.
Each peak list starts with a header that defines the experiment type and the order of dimensions. For instance, for HNCA.peaks:
# Number of dimensions 3 #FORMAT xeasy3D #INAME 1 HN #INAME 2 C #INAME 3 N #SPECTRUM HNCA HN C N 5 6.475 58.033 98.548 1 U 2.769E+02 0.000E+00 e 0 0 0 0 6 6.476 62.123 98.126 1 U 2.571E+01 0.000E+00 e 0 0 0 0 7 6.475 54.017 98.159 1 U 2.547E+01 0.000E+00 e 0 0 0 0
The first line specifies the number of dimensions (3 in this case). The '#SPECTRUM' lines gives the experiment type (HNCA, which refers to the corresponding experiment definition in the CYANA library), followed by an identifier for each dimension of the peak list (HN C N) that specifies which chemical shift is stored in the corresponding dimension of the peak list. These labels must match those in the corresponding experiment definition in the general CYANA library (see below). After the '#SPECTRUM' line follows one line for every peak. For example, the first peak in the 'HNCA.peaks' list has
- Peak number 5
- HN chemical shift 6.475
- C (CA) chemical shift 58.033
- N chemical shift 98.548
The other data are irrelevant for automated chemical shift assignment with FLYA. In particular, the peak volume or intensity (2.769E+02) is not used by the algorithm.
FLYA initialization script
The CYANA commands to run the automated assignment calculation are stored in two CYANA scripts or "macros".
One has the fixed name 'init.cya' and is executed automatically each time CYANA is started. It can also be called any one wants to reinitialize the program. It contains normally at least two commands that read the CYANA library and the protein sequence:
cyanalib read demo.seq
The command 'cyanalib' reads the standard CYANA library. When you start CYANA, the program reads the library and displays the full path name of the library file. You can open the standard library file to inspect, for example, the NMR experiment definitions that define which expected peaks are generated by FLYA. For instance, the definition for the HNCA spectrum is
SPECTRUM HNCA HN N C 0.980 HN:H_AMI N:N_AM* C_A* C_BYL C:C_ALI 0.800 HN:H_AMI N:N_AMI C_BYL C_ALI N_AMI C:C_ALI
The first line corresponds to the '#SPECTRUM' line in the peak list. It specifies the experiment name and a label for the atoms that are detected in each dimension of the spectrum. The number of labels defines the dimensionality of the experiment (3 in case of HNCA).
Each line below defines a (formal) magnetization transfer pathway that gives rise to an expected peak. Here