Group Leader/s



Group image

Group members (left to right):  Antonio Romero, Ágüeda González, Elena Santillana and F. Javier Medrano.

The Structural Biology of Proteins group focuses on two major research lines (i) the molecular basis of Acinetobacter baumannii infection, a life-threatening pathogen, (ii) the mechanism of carbohydrate recognition by lectins, which are involved in cancer development.

Infectious diseases are the leading cause of death worldwide and are a major challenge for public health. Despite recent advances in biochemical and structural studies of a series of pathogenic factors, a better understanding of targets involved in antibiotic resistance and microbial pathogenesis and how they are transferred is important to combat infectious diseases. Approaches to combat bacterial infection rely on, 1) the disruption of the bacteria growth cycle by preventing the synthesis and assembly of key components of bacterial processes and, 2) by inhibition of virulence traits. Our goal is to better understand the pathogenic mechanisms developed by gram-negative organisms (A. baumannii, P. aeruginosa, ..) in infection, using a structural approach.


β-lactamases and bacterial toxin-antitoxin systems. The number of class D carbapenemases identified in hospitals worldwide continues to grow significantly. Most of them have been isolated from gram-negative pathogens. Our more recent efforts attempt to correlate resistance mutations in new subfamilies of oxacillinases for the design of new antimicrobial agents. Furthermore, we are focusing in the structural characterization of the AbkA/AbkB toxin-antitoxin system in A. baumannii, related to virulence and involved in the successful dissemination of plasmids carrying the blaOXA-24/40-like gene, thus contributing to the plasmid stability.

Type VI secretion system (T6SS). Due to the difficulties inherent to this system, we have designed a strategy to address each individual component and subsequent assembly in silico. We have solved the crystal structure of Hcp (TssD) of A. baumannii characterizing the aggregation state by electron microscopy. Policlonal antibodies against Hcp confirmed that the T6SS of A. baumannii is active and functional in the AB0057 strain and in other different nosocomial strains of diverse origins. Very recently, we reported the crystal structure of VgrG1 from P. aeruginosa, TssL and TssK from A. baumannii. Our study reveals several remarkable structural features pointing to the possible roles of the two main segments of VgrG1: the head as a scaffold cargo domain and the β-roll spike with implications in the cell-membrane puncturing process and as a carrier of cognate toxins.

                                                                            Type VI Secretion System (T6SS)

Galectins. Galectins recognize and bind β-galactosides that are present in the great diversity of glycan structures located as glycoconjugates on the cell surface. The recognition and interpretation of the sugar (carbohydrate) code located in these glycoconjugates is carried out by its interaction with proteins, and the reading of this code is essential in a wide range of normal biological processes as well as in the pathogenesis of several human diseases. Galectins are closely related to these pathologies including overexpression in cancerous cells and cancer-associated stromal cells, particularly in those cell types that do not normally express the specific galectin. The final goal of this project is to characterize, structurally and biochemically, the binding properties of human galectins: Gal-1, Gal-3, Gal-4 and Gal-8 to a wide variety of mono- and multivalent glycostructures.








Ruiz FM, Medrano FJ, Ludwig A-K, Kaltner H, Shilova NV, Bovin NV, Gabius H-J, Romero A
Biomolecules 11, 1854

Structural Characterization of rat Galectin-5, an N-tailed monomeric proto-type-like

Gabius H-J, Cudic M, Diercks T, Kaltner H, Kopitz J, Mayo KH, Murphy PV, Oscarson S, Roy R, Schedlbauer A, Toegel S, Romero A
ChemBioChem 22, 1-25,  [2021]. 
What is the Sugar Code?

Klein ML, Romero A, Kaltner H, Percec V, Gabius H-J
Biophys J 120, 1031-1039, doi:10.1016/j.bpj.2020.11.020  [2021]. 
From examining the relationship between (corona)viral adhesins and galectins to glyco-perspectives

Diercks T, Medrano FJ, FitzGerald FG, Beckwith D, Pedersen MJ, Reihill M, Ludwig A-K, Romero A, Oscarson S, Cudic M and Gabius H-J
Chem. Eur. J. 27, 316-325  [2021]. 
Galectin‐Glycan Interaction: Guideline for Monitoring by 77Se NMR Spectroscopy and Solvent (H2O/D2O) Impact on Binding

Gato E, Vázquez-Ucha JC, Rumbo-Feal S, Álvarez-Fraga L, Vallejo JA, Martínez-Guitián M, Beceiro A, Ramos Vivas J, Sola Campoy PJ, Pérez-Vázquez M, Oteo Iglesias J, Rodiño-Janeiro BK, Romero A, Poza M, Bou G and Pérez A
PNAS, 117 (29) 17249-1725  [2020]. 
Kpi, a chaperone-usher pili system associated with the worldwide-disseminated high-risk clone Klebsiella pneumoniae ST-15

Ruiz FM, Lopez J, Ferrara CG, Santillana E, Espinosa YR, Feldman MF and Romero A.
J Bacteriol 202(17): e00210-20  [2020]. 
Structural characterization of TssL from Acinetobacter baumannii: a key component of the type VI secretion system



MINECO (BFU2016-77835-R) (2017-2019)

MINECO (BFU2014-55448-P) (2015-2016)

FP7-PEOPLE-2012-ITN (2012-2016)

CM S2010/BMD2353 (2012-2016)

MICINN (BFU2011-24615) (2011-2014)

MICINN CONSOLIDER-INGENIO (CSD2009-00088) (2011-2016)


More info

X-Ray equipment

Honeybee X8 crystallization robot