4JP7: High Resolution Structure Of A Papaya Barwin-like Protein (crystal Form 2)

The first crystal structure of a barwin-like protein, named carwin, has been determined at high resolution by single-wavelength anomalous diffraction (SAD) phasing using the six intrinsic S atoms present in the protein. The barwin-like protein was purified from Carica papaya latex and crystallized in the orthorhombic space group P212121. Using in-house Cu Kalpha X-ray radiation, 16 cumulative diffraction data sets were acquired to increase the signal-to-noise level and thereby the anomalous scattering signal. A sequence-database search on the papaya genome identified two carwin isoforms of 122 residues in length, both containing six S atoms that yield an estimated Bijvoet ratio of 0.93% at 1.54 A wavelength. A systematic analysis of data quality and redundancy was performed to assess the capacity to locate the S atoms and to phase the data. It was observed that the crystal decay was low during data collection and that successful S-SAD phasing could be obtained with a relatively low data multiplicity of about 7. Using a synchrotron source, high-resolution data (1 A) were collected from two different crystal forms of the papaya latex carwin. The refined structures showed a central beta-barrel of six strands surrounded by several alpha-helices and loops. The beta-barrel of carwin appears to be a common structural module that is shared within several other unrelated proteins. Finally, the possible biological function of the protein is discussed.
PDB ID: 4JP7Download
MMDB ID: 114127
PDB Deposition Date: 2013/3/19
Updated in MMDB: 2013/10
Experimental Method:
x-ray diffraction
Resolution: 1.05  Å
Source Organism:
Similar Structures:
Biological Unit for 4JP7: monomeric; determined by author and by software (PISA)
Molecular Components in 4JP7
Label Count Molecule
Protein (1 molecule)
Papaya Barwin-like Protein
Molecule annotation
Chemical (1 molecule)
* Click molecule labels to explore molecular sequence information.

Citing MMDB