5LAA

X-RAY STRUCTURE OF THE METHYLTRANSFERASE SUBUNIT A FROM METHANOTHERMUS FERVIDUS IN COMPLEX WITH COBALAMIN

Summary for 5LAA

• Entry DOI: 10.2210/pdb5laa/pdb
• Descriptor: Tetrahydromethanopterin S-methyltransferase subunit A, COBALAMIN (3 entities in total)
• Functional Keywords: methanogenesis, motor pump, membrane protein, methyltransferase, cobalamin, vitamin b12, coenzymem, rossmann fold, hyperthermophile, marine organism, transferase
• Biological source: Methanothermus fervidus (strain ATCC 43054 / DSM 2088 / JCM 10308 / V24 S); More
• Cellular location: Cell membrane ; Single-pass membrane protein : E3GWY7 E3GWY7
• Total number of polymer chains: 3
• Total formula weight: 58821.84

Authors

Wagner, T.,Ermler, U.,Shima, S. (deposition date: 2016-06-14, release date: 2016-07-06, Last modification date: 2024-05-08)

Primary citation

Wagner, T.,Ermler, U.,Shima, S.
MtrA of the sodium ion pumping methyltransferase binds cobalamin in a unique mode.
Sci Rep, 6:28226-28226, 2016

PubMed Abstract: In the three domains of life, vitamin B12 (cobalamin) is primarily used in methyltransferase and isomerase reactions. The methyltransferase complex MtrA-H of methanogenic archaea has a key function in energy conservation by catalysing the methyl transfer from methyl-tetrahydromethanopterin to coenzyme M and its coupling with sodium-ion translocation. The cobalamin-binding subunit MtrA is not homologous to any known B12-binding proteins and is proposed as the motor of the sodium-ion pump. Here, we present crystal structures of the soluble domain of the membrane-associated MtrA from Methanocaldococcus jannaschii and the cytoplasmic MtrA homologue/cobalamin complex from Methanothermus fervidus. The MtrA fold corresponds to the Rossmann-type α/β fold, which is also found in many cobalamin-containing proteins. Surprisingly, the cobalamin-binding site of MtrA differed greatly from all the other cobalamin-binding sites. Nevertheless, the hydrogen-bond linkage at the lower axial-ligand site of cobalt was equivalently constructed to that found in other methyltransferases and mutases. A distinct polypeptide segment fixed through the hydrogen-bond linkage in the relaxed Co(III) state might be involved in propagating the energy released upon corrinoid demethylation to the sodium-translocation site by a conformational change.

PubMed: 27324530
DOI: 10.1038/srep28226

Experimental method

X-RAY DIFFRACTION (3 Å)