Dynamic interplay between catalytic and lectin domains of GalNAc-transferases modulates protein O-glycosylation.
Protein O-glycosylation is controlled by polypeptide GalNAc-transferases (GalNAc-Ts) that uniquely feature both a catalytic and lectin domain. The underlying molecular basis of how the lectin domains of GalNAc-Ts contribute to glycopeptide specificity and catalysis remains unclear. Here we present the first crystal structures of complexes of GalNAc-T2 with glycopeptides that together with enhanced sampling molecular dynamics simulations demonstrate a cooperative mechanism by which the lectin domain enables free acceptor sites binding of glycopeptides into the catalytic domain. Atomic force microscopy and small-angle X-ray scattering experiments further reveal a dynamic conformational landscape of GalNAc-T2 and a prominent role of compact structures that are both required for efficient catalysis. Our model indicates that the activity profile of GalNAc-T2 is dictated by conformational heterogeneity and relies on a flexible linker located between the catalytic and the lectin domains. Our results also shed light on how GalNAc-Ts generate dense decoration of proteins with O-glycans.
BIFI, University of Zaragoza, BIFI-IQFR (CSIC) Joint Unit, Mariano Esquillor s/n, Campus Rio Ebro, Edificio I+D, Zaragoza 50018, Spain.
Erandi
E
Lira-Navarrete
BIFI, University of Zaragoza, BIFI-IQFR (CSIC) Joint Unit, Mariano Esquillor s/n, Campus Rio Ebro, Edificio I+D, Zaragoza 50018, Spain.
Matilde
M
de Las Rivas
Departamento de Química, Universidad de La Rioja, Centro de Investigación en Síntesis Química, E-26006 Logroño, Spain.
Ismael
I
Compañón
LMA, INA, Universidad de Zaragoza, 50018 Zaragoza, Spain.
María Carmen
MC
Pallarés
Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, School of Dentistry, University of Copenhagen, Copenhagen DK-2200, Denmark.
Yun
Y
Kong
Departament de Química Orgànica i IQTCUB, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain.
Javier
J
Iglesias-Fernández
1] Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK [2] Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av Prof Egas Moniz, 1649-028 Lisboa, Portugal.
Gonçalo J L
GJ
Bernardes
Departamento de Química, Universidad de La Rioja, Centro de Investigación en Síntesis Química, E-26006 Logroño, Spain.
Jesús M
JM
Peregrina
1] Departament de Química Orgànica i IQTCUB, Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain [2] ICREA, Passeig Lluís Companys 23, 08020 Barcelona, Spain.
Carme
C
Rovira
Centre de Biochimie Structurale, INSERM U1054, CNRS UMR 5048, Université Montpellier 1 and 2, 29 rue de Navacelles, 34090 Montpellier, France.
Pau
P
Bernadó
1] BIFI, University of Zaragoza, BIFI-IQFR (CSIC) Joint Unit, Mariano Esquillor s/n, Campus Rio Ebro, Edificio I+D, Zaragoza 50018, Spain [2] Departamento de Física Teórica, Universidad de Zaragoza, Zaragoza 50009, Spain.
Pierpaolo
P
Bruscolini
Copenhagen Center for Glycomics, Department of Cellular and Molecular Medicine, School of Dentistry, University of Copenhagen, Copenhagen DK-2200, Denmark.
Henrik
H
Clausen
1] LMA, INA, Universidad de Zaragoza, 50018 Zaragoza, Spain [2] Fundación ARAID, 50018 Zaragoza, Spain.
Anabel
A
Lostao
Departamento de Química, Universidad de La Rioja, Centro de Investigación en Síntesis Química, E-26006 Logroño, Spain.
Francisco
F
Corzana
1] BIFI, University of Zaragoza, BIFI-IQFR (CSIC) Joint Unit, Mariano Esquillor s/n, Campus Rio Ebro, Edificio I+D, Zaragoza 50018, Spain [2] Fundación ARAID, 50018 Zaragoza, Spain.
Ramon
R
Hurtado-Guerrero
D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D006020:Glycopeptides / Q000737:chemistry / Q000378:metabolism; D006031:Glycosylation; D037102:Lectins / Q000737:chemistry*; D008958:Models, Molecular; D056004:Molecular Dynamics Simulation; D017350:N-Acetylgalactosaminyltransferases / Q000737:chemistry* / Q000378:metabolism*; D009711:Nucleotides / Q000378:metabolism; D013329:Structure-Activity Relationship; D013379:Substrate Specificity; D000097763:Polypeptide N-acetylgalactosaminyltransferase
D006020:Glycopeptides; D037102:Lectins; D017350:N-Acetylgalactosaminyltransferases; D009711:Nucleotides; D000097763:Polypeptide N-acetylgalactosaminyltransferase