Protein crystallography beamline (PX-BL21) at Indus-2 synchrotron

Abstract

The protein crystallography beamline (PX-BL21), installed at the 1.5 T bending-magnet port at the Indian synchrotron (Indus-2), is now available to users. The beamline can be used for X-ray diffraction measurements on a single crystal of macromolecules such as proteins, nucleic acids and their complexes. PX-BL21 has a working energy range of 5-20 keV for accessing the absorption edges of heavy elements commonly used for phasing. A double-crystal monochromator [Si(111) and Si(220)] and a pair of rhodium-coated X-ray mirrors are used for beam monochromatization and manipulation, respectively. This beamline is equipped with a single-axis goniometer, Rayonix MX225 CCD detector, fluorescence detector, cryogenic sample cooler and automated sample changer. Additional user facilities include a workstation for on-site data processing and a biochemistry laboratory for sample preparation. In this article the beamline, other facilities and some recent scientific results are briefly described.

Mixed‐Stack Charge Transfer Crystals of Pillar[5]quinone and Tetrathiafulvalene Exhibiting Ferroelectric Features

“…Notably, this CT complex is found to crystallize solely in 1:1 stoichiometry, irrespective of the number of equivalence of TTF employed. The crystal structure, obtained from single crystal synchrotron X‐ray diffraction study, clearly unveiled the pivotal role of π–π interactions in the solid‐state. Remarkably, among the five p ‐benzoquinones of P5Q , four are involved in π‐stacking interactions: one with TTF at a distance of 3.523(2) Å, and other three with the neighboring P5Q s at distances of 3.586(2), 3.702(2), and 3.713(2) Å.…”

Catalytic triad heterogeneity in S51 peptidase family: Structural basis for functional variability

“…The X‐ray diffraction studies for frozen crystals of PepEdr were carried out at protein crystallography beamline (PX‐BL21) of Indus‐2 synchrotron, RRCAT, India . The diffraction images were collected from cryo‐cooled crystal with 1° oscillation at 0.979470 Å wavelength for PepEdr with N‐terminal 6 × His tag and at 0.977790 Å wavelength for PepEdr with C‐terminal 6 × His tag.…”

Structures and activities of widely conserved small prokaryotic aminopeptidases‐P clarify classification of M24B peptidases

“…Crystals were cryoprotected by supplementing crystallization condition with 20% glycerol and flash frozen in liquid nitrogen. X‐ray diffraction data were collected on beamline PX‐BL21, Indus‐2 (RRCAT, Indore, India) …”

“…X-ray diffraction data were collected on beamline PX-BL21, Indus-2 (RRCAT, Indore, India). 28 Diffraction images were integrated and scaled using XDS. 29 Structures were solved by molecular replacement (MR) using PHASER 30 suite on the CCP4 31 platform.…”