XALOC - BL13

	First Users 18 July 2012 XALOC starts user operation with the group of M. Coll, from IBMB-CSIC.
	Results from the very first day of user operation 18 July 2012 Structure of a herpesvirus nuclease-antiviral complex. Data collected at Xaloc on July 18th, 2012. (Bongarzone, S., Nadal, M. & Coll, M., IBMB)
	First High-impact publication with XALOC data 21 Feb 2014 The 3D structures have revealed why a given Auxin Response Factor (ARF, plant transcription factor) is capable of activating a single set of genes, while other ARFs that are very similar with only slight differences trigger a distinct set (R. Boer, M. Coll, et al. Cell, 2014 156:577)

Staff

Roeland Boer: Beamline responsible
Fernando Gil: Beamline Scientist

Xavi Carpena : Beamline Scientist
Bárbara Calisto: Post-doc Scientist

José Ávila, Alberto Rubio : Electronics Engineers
Gabriel Jover: Controls Engineer

Xavier Fariña : Electronics Technician
Alejandro Enrique: Mechanics Technician

Beamline characteristics

The beam size will be fitted to the crystal dimensions by (a) adjusting the focus of the mirrors along the beam path, and (b) having two operation modes of the beamline: focused and unfocused.

In unfocused configuration, one or both mirrors are removed from the photon beam path, resulting in a very small beam divergence of less than 0.03 mrad vertically. This mode can be especially useful for large macromolecular complexes with large unit cell parameters. In focused configuration both mirrors can focus the beam to 50×6 um² FWHM (H×V) on small or microcrystals, while at the same time keeping a small and useful vertical divergence (0.1 mrad). In addition, the mirrors allow variable focusing (defocusing) if matching the size of the x-ray beam to the dimensions of the crystals or if focusing at the detector (which can be placed at any distance between 80 mm to 1300 mm from sample) are required. In this case, the beam size at sample position can range from 50×6 um² to 300×300 um² (H×V). In order to avoid x-ray beam deformations caused by the optics when defocusing, slope errors of the mounted mirrors have been reduced to 70 nrad rms and the monochromator crystal can work near the zero expansion temperature of Silicon (124 K).

Technical Description

• Photon source
• Optics
• End Station

EU projects

XALOC is a partner of the BioStruct-X project funded by the Seventh Framework Programme (FP7) of the European Commission, for Macromolecular Crystallography beamlines Transnational Access. EU Funding (travel, accomodation and subsitence costs) for EU BAG proposals allocated with beamtime at XALOC is available through a Call for Proposals. For more information, please go to:

  http://www.biostruct-x.eu/

Beamline documentation

• Original Proposal of the beamline (2005)
• Conceptual Design (2006)
• SRI Conference (2006, Daegu, Korea) - AIP proceedings contribution
  
• Minutes 1a Reunión de Usuarios de Líneas de Luz de Cristalografía Macromolecular de España (22 Octubre 2007)
• Poster XALOC in 4th Annual Meeting BioXHit (16-18 April 2008)
• Poster XALOC in Spanish Synchrotron Users Meeting (AUSE4, 15-18 September 2009) 

• Poster XALOC in 2011 IUCr General Congress (Madrid, 22-29 August 2011)
  
• Reference paper of the XALOC beamline (J. Synch. Rad. 21, 2014)