7BGS

Archeal holliday junction resolvase from Thermus thermophilus phage 15-6

Summary for 7BGS

• Entry DOI: 10.2210/pdb7bgs/pdb
• Descriptor: Holliday junction resolvase, SULFATE ION (3 entities in total)
• Functional Keywords: archeal holliday junction resolvase helicase dna binding enzyme phage 15-6 thermus thermophilus, recombination
• Biological source: Thermus thermophilus phage 15-6; More
• Total number of polymer chains: 2
• Total formula weight: 38684.39

Authors

Hakansson, M.,Ahlqvist, J.,Linares Pasten, J.A.,Jasilionis, A.,Nordberg Karlsson, E.,Al-Karadaghi, S. (deposition date: 2021-01-08, release date: 2022-01-19, Last modification date: 2024-10-23)

Primary citation

Ahlqvist, J.,Linares-Pasten, J.A.,Hakansson, M.,Jasilionis, A.,Kwiatkowska-Semrau, K.,Friðjonsson, O.H.,Kaczorowska, A.K.,Dabrowski, S.,Aevarsson, A.,Hreggviðsson, G.O.,Al-Karadaghi, S.,Kaczorowski, T.,Nordberg Karlsson, E.
Crystal structure and initial characterization of a novel archaeal-like Holliday junction-resolving enzyme from Thermus thermophilus phage Tth15-6.
Acta Crystallogr D Struct Biol, 78:212-227, 2022

PubMed Abstract: This study describes the production, characterization and structure determination of a novel Holliday junction-resolving enzyme. The enzyme, termed Hjc_15-6, is encoded in the genome of phage Tth15-6, which infects Thermus thermophilus. Hjc_15-6 was heterologously produced in Escherichia coli and high yields of soluble and biologically active recombinant enzyme were obtained in both complex and defined media. Amino-acid sequence and structure comparison suggested that the enzyme belongs to a group of enzymes classified as archaeal Holliday junction-resolving enzymes, which are typically divalent metal ion-binding dimers that are able to cleave X-shaped dsDNA-Holliday junctions (Hjs). The crystal structure of Hjc_15-6 was determined to 2.5 Å resolution using the selenomethionine single-wavelength anomalous dispersion method. To our knowledge, this is the first crystal structure of an Hj-resolving enzyme originating from a bacteriophage that can be classified as an archaeal type of Hj-resolving enzyme. As such, it represents a new fold for Hj-resolving enzymes from phages. Characterization of the structure of Hjc_15-6 suggests that it may form a dimer, or even a homodimer of dimers, and activity studies show endonuclease activity towards Hjs. Furthermore, based on sequence analysis it is proposed that Hjc_15-6 has a three-part catalytic motif corresponding to E-SD-EVK, and this motif may be common among other Hj-resolving enzymes originating from thermophilic bacteriophages.

PubMed: 35102887
DOI: 10.1107/S2059798321012298

Experimental method

X-RAY DIFFRACTION (2.5 Å)