Structure of the N-terminal domain of Euprosthenops australis dragline silk suggests that conversion of spidroin dope to spider silk involves a conserved asymmetric dimer intermediate

A crystal structure of an asymmetric dimer of the N-terminal domain of the Euprosthenops australis dragline silk protein is reported. The structure is proposed to represent an intermediate state in spider silk formation.

Crystal structures of the naturally fused CS and cytochrome b₅ reductase (b₅R) domains of Ncb5or reveal an expanded CS fold, extensive CS–b₅R interactions and productive binding of the NAD(P)⁺ nicotinamide ring

Ncb5or is a multi-domain redox enzyme involved in disease pathways. Structures of the naturally fused CS and cytochrome b₅ reductase domains are reported, which provide a window into the function of Ncb5or and reveal distinct differences relative to previously reported CS and cytochrome b₅ reductase structures.

Structures of the transcriptional regulator BgaR, a lactose sensor

The crystal structure of the transcriptional regulator BgaR with no sugar added is presented, along with those of its complexes with lactose and lactulose. The structure is related to that of the transcriptional regulator AraC, but shows differences in the effector-binding pocket.

ATP-specificity of succinyl-CoA synthetase from Blastocystis hominis

To test the theory of `gatekeeper' residues, the nucleotide-binding domains of Blastocystis hominis succinyl-CoA synthetase and mutant proteins were produced, purified and crystallized. The structures of the complexes with Mg²⁺-ADP show why the enzyme is ATP-specific.

LAT1 (SLC7A5) and CD98hc (SLC3A2) complex dynamics revealed by single-particle cryo-EM

Insight is provided into the dynamic interactions of LAT1 and CD98hc and their role in the transport cycle of the complex.

Combining random microseed matrix screening and the magic triangle for the efficient structure solution of a potential lysin from bacteriophage P68

An efficient optimization screen was devised using random microseed matrix screening to quickly derivatize crystals using an iodinated phasing ligand.

Crystal structures of the closed form of Mycobacterium tuberculosis di­hydrofolate reductase in complex with di­hydrofolate and antifolates

Structures of dihydrofolate reductase from Mycobacterium tuberculosis in complex with dihydrofolate and antifolates show key conformational changes and different binding modes in the protein structure and ligands, respectively, that reflect the plasticity of this enzyme. Several of the movements associated with the dihydrofolate-binding site may be involved in the catalytic cycle of the enzyme, while the different binding modes of the ligands are associated with their distinct functional groups that have to adopt alternative poses to fit into the active site of the protein.

Barbara Wharton Low (1920–2019)

Obituary for Barbara Wharton Low, an important figure in the history of structure determination and our understanding of chemistry and physics today.