NMR‐derived folate‐bound structure of dihydrofolate reductase 1 from the halophile Haloferax volcanii

Abstract

Folate binds to dihydrofolate reductase (DHFR) to form a binary complex whose structure maintains the overall configuration of the enzyme; however, some significant changes are evident when a comparison is made to the enzyme. The structure of DHFR1 from the halophilic Halopherax volcanii was solved in its folate-bound form using nuclear magnetic resonance spectroscopy. NOE data obtained from the (15)N-NOESY-HSQC and (13)C-NOESY-HSQC experiments of the triply labeled ((1)H, (13)C, and (15)N) binary complex were used as input for the structure calculation with the Crystallography and Nuclear Magnetic Resonance System program. The resulting family of structures was compared with the enzyme solved by both nuclear magnetic resonance and X-ray crystallography and also to the mesophilic folate-bound enzyme from Escherichia coli. The binary complex exhibited less convergence of structure in the alpha2-helix and differences in the hinge residues D39 and A94. In comparison to the previously reported mesophilic binary complex solved by X-ray crystallography, the halophilic binary complex reported here does not agree with the convergence of the M20 loop to a single structure. The corresponding L21 loop of the halophilic binary complex family of structures solved by nuclear magnetic resonance indicates variability in this region.

Gates of Enzymes

“…NMR techniques have been used to measure the rate of exchange between the open and the closed conformations of triosephophate isomerase, 77,78 HIV-1 protease, 79 and dihydrofolatereductase. 80,81 Overall, the utility of NMR for studying distant effects of mutations on protein dynamics suggests that it has great potential for investigating gating mechanisms. 9 …”

Asgard archaea are diverse, ubiquitous, and transcriptionally active microbes

“…By contrast, Heimdallarchaeota and Odinarchaeota appeared to reduce inorganic carbon by using one of the C1 carriers through THF-WL or THMPT-WL pathway, respectively. Typically, THF is a C1 carrier in bacterial acetogens 29 and 9 some halophilic archaea 30 . Although Heimdallarchaeota have been mainly identified in saline environments ( Fig.…”

A 5-formyltetrahydrofolate cycloligase paralog from all domains of life: comparative genomic and experimental evidence for a cryptic role in thiamin metabolism

“…d Distribution among archaea of folates and folate analogs in relation to distribution of genes encoding 5-FCL and COG0212. The figure shows only species from genera in which chemical, biochemical, or genomic evidence supports the presence of folates or folate analogs such as methanopterin and sarcinapterin (Worrell and Nagle 1988; van de Wijngaard et al 1991; White 1988, 1991, 1993; Gorris and van der Drift 1994; Lin and Sparling 1998; Lin and White 1988; Buchenau and Thauer 2004; Grochowski et al 2007; Levin et al 2007; Falb et al 2008; Boroujerdi and Young 2009). The phylogeny is from Spang et al (2010)…”