Introduction to crystallographic refinement of macromolecular atomic models. Addendum

Abstract

The first attempt at modelling of deformation density was in 1950 when R. Franklin published her observation of the influence of the bonding effects on the intensities of structure factors and suggested to describe the deformation density by point scatterers at the C–C bonds.

KEYWORDS:

• X-ray diffraction
• deformation density
• subatomic resolution
• multipolar model
• interatomic scatterers

Acknowledgements

We thank Professor Alexandre Nazarenko who pointed us out the article [2] by R. Franklin. We also thank Professor John Helliwell for pointing out W.H. Bragg’s work [6] and its historical context described in the book by A. Authier [5], as well as for his support of our manuscript. AU acknowledges the infrastructure of Instruct-ERIC and that of French Infrastructure for Integrated Structural Biology FRISBI [ANR-10-INBS-05].

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Alexandre G. Urzhumtsev http://orcid.org/0000-0002-1002-3041

Vladimir Y. Lunin http://orcid.org/0000-0003-1235-1206

Additional information

Notes on contributors

Alexandre G. Urzhumtsev

Alexandre G. Urzhumtsev is a full professor at the Université de Lorraine, Nancy, and a researcher at the IGBMC (Institut de Génétique et de Biologie Moléculaire et Cellulaire) à Illkirch, France. After the Kolmogorov's school-internat and the Faculty of Computational Mathematics at the Moscow State University (1978), he started to work in the Research Computing Center of Russian Academy of Sciences in Pushchino. He got his PhD in X-ray macromolecular crystallography in 1985 (Institute of Crystallography, Moscow). In 1991 he moved to France. He got his Habilitation in the University of Strasbourg in 1997. His main research interests are development of computational methods and programs for macromolecular structure solution, refinement and validation, as well as solution of ‘difficult’ structures. He works on refinement problems for more than 40 years.

Vladimir Y. Lunin

Prof. Vladimir Y. Lunin is a Chief Researcher in the Keldysh Institute of Applied Mathematics of Russian Academy of Sciences. He graduated from the Department of Mechanics and Mathematics of Lomonosov Moscow State University and got PhD in differential equations and mathematical physics in 1977^th. He was awarded the degree of Doctor of Science in Crystallography (habilitation) by Shubnikov Institute of Crystallography RAS in 1992. In 1976 he headed the computer support and software development for biological crystallography in the Research Computing Center of Russian Academy of Sciences in Pushchino (from 1992 Institute of Mathematical Problems of Biology, from 2016 the department of Keldysh Institute of Applied Mathematics RAS). In the end of 70's, together with Alexandre Urzhumtsev, he started to work on macromolecule refinement problmes. Another branch of his scientific interest is the low-resolution ab initio phasing in biological crystallography and single particle studies.