6LK4

Crystal structure of GMP reductase from Trypanosoma brucei in complex with guanosine 5'-triphosphate

Replaces:  5X8O

Summary for 6LK4

• Entry DOI: 10.2210/pdb6lk4/pdb
• Descriptor: Guanosine 5'-monophosphate Reductase, GUANOSINE-5'-TRIPHOSPHATE, PHOSPHATE ION, ... (4 entities in total)
• Functional Keywords: trypanosoma brucei, 5'-monophosphate reductase, guanosine 5'-triphosphate, cystathionine beta synthase motif, oxidoreductase
• Biological source: Trypanosoma brucei brucei
• Total number of polymer chains: 1
• Total formula weight: 54456.39

Authors

Mase, H.,Otani, T.,Imamura, A.,Nishimura, S.,Inui, T. (deposition date: 2019-12-18, release date: 2020-03-18, Last modification date: 2023-11-22)

Primary citation

Imamura, A.,Okada, T.,Mase, H.,Otani, T.,Kobayashi, T.,Tamura, M.,Kubata, B.K.,Inoue, K.,Rambo, R.P.,Uchiyama, S.,Ishii, K.,Nishimura, S.,Inui, T.
Allosteric regulation accompanied by oligomeric state changes of Trypanosoma brucei GMP reductase through cystathionine-beta-synthase domain.
Nat Commun, 11:1837-1837, 2020

PubMed Abstract: Guanosine 5'-monophosphate reductase (GMPR) is involved in the purine salvage pathway and is conserved throughout evolution. Nonetheless, the GMPR of Trypanosoma brucei (TbGMPR) includes a unique structure known as the cystathionine-β-synthase (CBS) domain, though the role of this domain is not fully understood. Here, we show that guanine and adenine nucleotides exert positive and negative effects, respectively, on TbGMPR activity by binding allosterically to the CBS domain. The present structural analyses revealed that TbGMPR forms an octamer that shows a transition between relaxed and twisted conformations in the absence and presence of guanine nucleotides, respectively, whereas the TbGMPR octamer dissociates into two tetramers when ATP is available instead of guanine nucleotides. These findings demonstrate that the CBS domain plays a key role in the allosteric regulation of TbGMPR by facilitating the transition of its oligomeric state depending on ligand nucleotide availability.

PubMed: 32296055
DOI: 10.1038/s41467-020-15611-3

Experimental method

X-RAY DIFFRACTION (2.503 Å)