issue contents
November 2012 issue
editorial
Free
research papers
The haemoglobin (Hb) of the extinct woolly mammoth has been recreated using recombinant genes expressed in Escherichia coli. The crystal structures of mammoth Hb have been determined in the deoxy, carbonmonoxy and aquo-met forms.
A new mechanism for hydrolysis of the amide bond in GlcNAc-Ins by MshB, which is supported by structural evidence, is proposed. In particular, the involvement of Tyr142, which was predicted on the basis of kinetic and mutagenic studies, is confirmed.
PDB reference: MshB, 4ewl
The crystal structure of the extended-spectrum β-lactamase OXY-1-1 has been determined at 1.93 Å resolution. Structural features around the catalytic cavity help to broaden the substrate profile of the enzyme.
PDB reference: OXY-1-1, 3byd
The crystal structure of endo-β-D-1,4-mannanase from Chrysonilia sitophila has been solved at 1.40 Å. The enzyme has mixed activity as both an endo-mannanase and endo-glucanase and the crystal structure revealed a unique arrangement of three surface loops surrounding the active site, altering the topography of the binding cleft.
PDB reference: endo-β-D-1,4-mannanase, 4awe
The TrpF structure from the hyperthermophilic archaeon P. furiosus is described at 1.75 Å resolution. Structural comparison with other thermophilic TrpF proteins suggests a mechanism for thermal stability.
PDB reference: PfTrpF, 4aaj
Crystal structures of ribosome-inactivating protein (RIP) from barley seeds have been determined in free, AMP-bound and adenine-bound states. These data revealed a unique activation mechanism for a type I RIP from a monocotyledonous crop.
This paper describes the crystal structure of the globular part of the human prion protein bound to the CDR of the Fab fragment of the POM1. The epitope of the huPrPc for POM1 constitutes the N-terminus of helix α1, a portion of the polypeptide chain linking sheet β1 and helix α1 and several residues on helix α3; the measured Kd is 4.5 × 10−7 M.
PDB reference: POM1 Fab–huPrPc complex, 4dgi
The origins of the diversity in the SHG signal from protein crystals are investigated and potential protein-crystal coverage by SHG microscopy is assessed.
Error-estimation-guided rebuilding of de novo models increases the success rate of ab initio phasing
Focused rebuilding of coarse-grained models guided by the probabilistic estimation of residue errors has increased the success rate of ab initio phasing by de novo models using molecular replacement.
This report presents the crystal structure of L-amino-acid ligase from B. licheniformis. This structure provides an initial step towards the efficient industrial production of various useful dipeptide agents.
PDB reference: L-amino-acid ligase, 3vot
An account of the detection of severe diffraction anisotropy, rotational pseudosymmetry and twinning during the refinement of the rotaviral nonstructural protein NSP4 and a description of corrections for these factors leading to successful refinement of the structure are presented.
The structures of a substrate-free but Zn2+-bound state of MtaA and its complex with substrate (coenzyme M) and Zn2+ are reported. MtaA is one of the three subunits of the methanol–coenzyme M–methyltransferase complex of M. mazei responsible for the conversion of methanol to methylated coenzyme M.
The hexameric crystal structure of geranyl pyrophosphate methyltransferase in complex with bona fide substrate provides the first model of enzymatic C-methylation of an isoprenoid pyrophosphate.
An HsdM structure of a putative type I restriction enzyme was revealed, which shows a close enzymatic relationship with N6 DNA TaqI methyltransferase.
PDB reference: vvHsdM, 3ufb
short communications
The cryoprotecting agent ethylene glycol is shown to affect the structural and spectroscopic properties of cyan fluorescent proteins, shedding new light on fluorescent protein dynamics.
PDB reference: Cerulean cryoprotected with EG, 4as8
A low flow rate liquid microjet method for delivery of hydrated protein crystals to X-ray lasers is presented. Linac Coherent Light Source data demonstrates serial femtosecond protein crystallography with micrograms, a reduction of sample consumption by orders of magnitude.
obituaries
Free
Obituary for Professor Dame Louise Napier Johnson.