Structural and biochemical characterization of the relaxosome auxiliary proteins encoded on the Bacillus subtilis plasmid pLS20
Crespo, Isidro (ALBA Laboratori de Llum de Sincrotró)
Bernardo, Nerea (ALBA Laboratori de Llum de Sincrotró)
Cuppari, Anna (ALBA Laboratori de Llum de Sincrotró)
Calisto, Bárbara Luísa Machado (ALBA Laboratori de Llum de Sincrotró)
Val-Calvo, Jorge (Centro de Biología Molecular Severo Ochoa)
Miguel-Arribas, Andrés (Centro de Biología Molecular Severo Ochoa)
Meijer, Wilfried J. J. (Centro de Biología Molecular Severo Ochoa)
Carpena, Xavi (ALBA Laboratori de Llum de Sincrotró)
Gil-Ortiz, Fernando (ALBA Laboratori de Llum de Sincrotró)
Malfois, Marc (ALBA Laboratori de Llum de Sincrotró)
Boer, D. Roeland (ALBA Laboratori de Llum de Sincrotró)

Fecha:	2022
Resumen:	Bacterial conjugation is an important route for horizontal gene transfer. The initial step in this process involves a macromolecular protein-DNA complex called the relaxosome, which in plasmids consists of the origin of transfer (oriT) and several proteins that prepare the transfer. The relaxosome protein named relaxase introduces a nick in one of the strands of the oriT to initiate the process. Additional relaxosome proteins can exist. Recently, several relaxosome proteins encoded on the Bacillus subtilis plasmid pLS20 were identified, including the relaxase, named Rel, and two auxiliary DNA-binding factors, named Aux1 and Aux2. Here, we extend this characterization in order to define their function. We present the low-resolution SAXS envelope of the Aux1 and the atomic X-ray structure of the C-terminal domain of Aux2. We also study the interactions between the auxiliary proteins and the full-length Rel, as well as its separate domains. The results show that the quaternary structure of the auxiliary protein Aux1 involves a tetramer, as previously determined. The crystal structure of the C-terminal domain of Aux2 shows that it forms a tetramer and suggests that it is an analog of TraM of plasmid F. This is the first evidence of the existence of a TraM analog in gram positive conjugative systems, although, unlike other TraM analogs, Aux2 does not interact with the relaxase. Aux1 interacts with the C-terminal domain, but not the N-terminal domain, of the relaxase Rel. Thus, the pLS20 relaxosome exhibits some unique features despite the apparent similarity to some well-studied G- conjugation systems.
Ayudas:	Ministerio de Economía y Competitividad BIO2016-77883-C2-1-P Agencia Estatal de Investigación PID2019-108778GB-C21 Agencia Estatal de Investigación PID2020-117028 GB-I00 Ministerio de Economía y Competitividad BIO2016-77883-C2-2-P Ministerio de Economía y Competitividad FIS2015-72574-EXP
Derechos:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, i la comunicació pública de l'obra, sempre que no sigui amb finalitats comercials, i sempre que es reconegui l'autoria de l'obra original. No es permet la creació d'obres derivades.
Lengua:	Anglès
Documento:	Article ; recerca ; Versió publicada
Materia:	Structural biology ; Bacterial conjugation ; Relaxosome ; Auxiliary protein ; DNA binding protein ; Ribbon-Helix-Helix ; Antibiotic resistance ; Firmicutes ; Horizontal gene transfer
Publicado en:	Computational and Structural Biotechnology Journal, Vol. 20 (January 2022) , p. 757-765, ISSN 2001-0370

DOI: 10.1016/j.csbj.2021.12.041
PMID: 35198129

9 p, 1.5 MB

El registro aparece en las colecciones:
Documentos de investigación > Documentos de los grupos de investigación de la UAB > Centros y grupos de investigación (producción científica) > Ciencias > El Sincrotrón ALBA
Artículos > Artículos de investigación
Artículos > Artículos publicados