IUCr Journals Poster Prize awarded to NARILIS PhD student Elise Pierson at the Belgian Crystallography Symposium 2021!

The chemist Elise Pierson joined the Laboratory of Structural Biological Chemistry (CBS) of the UNamur in September 2018 as a PhD research fellow of the F.R.S.-FNRS. The CBS lab is directed by Prof. Johan Wouters and is specialized in the production, purification and characterization of enzymes of pharmaceutical interests. With a strong expertise in protein crystallography, the lab contributes to advancing structure-based drug design. Their medicinal chemistry projects are conducted under the umbrella of the Namur Medicine & Drug Innovation Center (NAMEDIC).

The PhD thesis of Elise Pierson focuses in particular on phosphoserine phosphatases, of which SerB from Brucella melitensis, an essential enzyme required for intracellular replication and full virulence, and a drug target for the development of new anti-brucellosis agents. Her work has recently unveiled the first crystal structure of the enzyme, at a resolution of 1.8 Å.

On March 17, 2021, Elise presented her new findings on the architecture of B. melitensis SerB at the virtual edition of the Belgian Crystallography Symposium (BSC-11). Her poster presentation, entitled “Deciphering the structural features of Brucella melitensis SerB, a single-ACT domain phosphoserine phosphatase” attracted the attention and was awarded the IUCr (International Union of Crystallography) Journals Poster Prize!

Contact: elise.pierson@unamur.be

11th Belgian Crystallography Symposium –17 March 2021 – Virtual Meeting 


Elise Pierson and Johan Wouters

Laboratoire de Chimie Biologique Structurale (CBS), Namur Medicine and Drug Innovation Center (Namedic), Namur Research Institute for Life Sciences (NARILIS) - Université de Namur, 5000 Namur, Belgique

Keywords: phosphoserine phosphatase, SerB, L-serine, ACT, PSP

Phosphoserine phosphatases (PSPs) are enzymes that catalyze the last step of the phosphorylated L-serine pathway in most organisms. Due to this essential metabolic role or due to the gain of virulence-related functions, PSPs are implicated in the pathogenicity of several bacteria (1-3). In Brucella, the enzyme (SerB) has been shown to be required for intracellular replication and full virulence (3), which makes it an interesting target for the development of new agents with antibrucellosis activity. For structure-based drug design purposes, SerB from Brucella melitensis (BrmeSerB) was crystallized and we present here the first crystal structure of the enzyme, at a resolution of 1.8 Å. BrmeSerB exhibits two distinct domains: a catalytic PSP domain, with bound Mg2+ and phosphate in the active site, and an ACT domain, whose identification has been made possible through the X-ray diffraction experiment. This architecture makes SerB a remarkable PSP, as other homologous PSPs of known structure consist of only one PSP domain alone or followed by two consecutive ACT domains. In this work, we describe the structure of BrmeSerB and compare it with its closest crystalized homologues.


[1] Shree, S. et al. (2016). Cellular and molecular life sciences, 73(17), 3401-3417.

[2] Jung, S. K. et al. (2012). Bioorganic & medicinal chemistry letters, 22(5), 2084-2088.

[3] Révora, V., Marchesini, M. I., & Comerci, D. J. (2020). Infection and immunity, 88(2).