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Figure 7
Comparison of MAT(α2)4(βV2)2 complex with MAT(α2)4. (a) Superposition of SAMe-bound MAT(α2)4 (PDB entry 2p02 in blue) and SAMe-bound MAT(α2)4 (slate, red) from the complex MAT(α2)4(βV2)2; in the closed state both structures are similar. (b) Superposition of apo-MAT(α2)2 from Burkholderia pseudomallei (PDB entry 3iml , Baugh et al., 2013BB40, in pink) with the SAMe-bound MAT(α2)2 (PDB entry 2p02 in blue); in the absence of SAMe only the gating loop is disordered. (c) Superposition of SAMe-bound MAT(α2)2 (PDB entry 2p02 in blue) with MAT(α2)2 after MATβV2 binding; the open state in this case shows two additional flexible loops, near the inserted MATβV2 C-terminus. (d) ATP was added to MAT(α2)4, MAT(α2)4(βV1Δ16)2, MAT(α2)4(βV2)2 and MAT(α2)4(βV1)2 pre-incubated with 5–200 µM of methionine then SAMe formation was quantified using UPLC–MS/MS. It shows that the Vmax of MATα2β complexes are higher depending on the variant of MATβ.

IUCrJ
Volume 1| Part 4| June 2014| Pages 240-249
ISSN: 2052-2525
doi:10.1107/S2052252514012585