Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.21.4 (trypsin)
 42,187 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Five test structures (orthorhombic and trigonal trypsin, cubic and rhombohedral insulin and thaumatin) have been solved by the SAD (single-wavelength anomalous diffraction) method using highly redundant data collected at 100 K with a CCD detector, rotating-anode generator and three-circle goniometer. The very weak anomalous scattering (primarily from sulfur) was sufficient to locate all the anomalous scatterers using the integrated direct and Patterson methods in SHELXD. These positions and occupancies were used without further refinement to estimate phases that were extended to native (in-house) resolution by the sphere of influence algorithm in SHELXE. The final map correlation coefficients relative to the anisotropically refined structures were in the range 0.81-0.97. The use of highly redundant medium-resolution laboratory data for sulfur-SAD phasing combined with high-resolution synchrotron native data for phase expansion and structure refinement clearly has considerable potential.
 ...
PMID:In-house measurement of the sulfur anomalous signal and its use for phasing. 1265 88

The DOF protein, SAD, previously shown to be a transcriptional activator in barley aleurone cells upon seed germination, also has an important role in gene regulation during endosperm development. mRNA was detected in early (10 days after flowering) developing barley seeds where it accumulated in the starchy endosperm, aleurone cells, nucellar projection, vascular tissues and the immature embryo, as shown by RT-PCR and in situ hybridization analyses. The SAD protein, expressed in bacteria, binds to oligonucleotides containing the prolamine box, 5'-A/TAAAG-3'sequence, derived from the promoter regions of the endosperm-specific genes Hor2 and Itr1, encoding a B-hordein and trypsin-inhibitor BTI-CMe, respectively. SAD competed for the same binding sites with another endosperm-expressed DOF protein, BPBF. Transient expression experiments in co-bombarded developing endosperms demonstrated that SAD trans-activated transcription from Hor2 and Itr1 promoters through binding to the intact DOF motifs. When the two DOF factors are co-bombarded together an additive effect was observed upon the expression of the Itr1 gene. In-frame fusion of the Sad ORF to the reporter green fluorescent protein gene directs the fluorescence expression to the nucleus in transiently transformed onion epidermal layers. The visualization of fluorescence in the nucleus of onion cells, using the bimolecular fluorescent complex (BiFC) approach, has shown the in vivo interaction between SAD and the R2R3MYB protein GAMYB. The interaction in plant cells has also been documented for the DOF protein BPBF and GAMYB, but nuclear interaction could not be detected between BPBF and SAD by this procedure.
 ...
PMID:The DOF protein, SAD, interacts with GAMYB in plant nuclei and activates transcription of endosperm-specific genes during barley seed development. 1591 80

Phasing of the crystal structures of four standard proteins (lysozyme, trypsin, glucose isomerase and thaumatin) and a novel 69 kDa protein from Thermus thermophilus, TT0570, was performed using the single-wavelength anomalous diffraction of S atoms intrinsically present within the native protein molecules. To utilize the sulfur anomalous diffraction, the data sets were collected using the loopless data-collection method with chromium Kalpha X-rays of wavelength 2.29 A. Three phasing methods, MLPHARE, SHARP and OASIS-2004, were tested in combination with the DM or SOLOMON density-modification method. The results showed that the solvent contents are still an important factor for phasing with the S-SAD method, even when longer wavelength Cr Kalpha radiation is used. Of the three procedures, the improved direct phasing of OASIS-2004 with its implemented fragment feedback to the direct-method probability calculation gave the best results in determining the initial phases. For all five proteins, almost the entire models could be built automatically.
 ...
PMID:Comparison of phasing methods for sulfur-SAD using in-house chromium radiation: case studies for standard proteins and a 69 kDa protein. 1623 32