Visualizing Ferroelectric Uniformity of HfZrO Films Using X-ray Mapping.

HfZrO (HZO) is a complementary metal-oxide-semiconductor (CMOS)-compatible ferroelectric (FE) material with considerable potential for negative capacitance field-effect transistors, ferroelectric memory, and capacitors. At present, however, the deployment of HZO in CMOS integrated circuit (IC) technologies has stalled due to issues related to FE uniformity. Spatially mapping the FE distribution is one approach to facilitating the optimization of HZO thin films.

The First Residue of the PWWP Motif Modulates HATH Domain Binding, Stability, and Protein-Protein Interaction.

Hepatoma-derived growth factor (hHDGF) and HDGF-related proteins (HRPs) contain conserved N-terminal HATH domains with a characteristic structural motif, namely the PWWP motif. The HATH domain has attracted attention because of its ability to bind with heparin/heparan sulfate, DNA, and methylated histone peptide. Depending on the sequence of the PWWP motif, HRP HATHs are classified into P-type (Pro-His-Trp-Pro) and A-type (Ala-His-Trp-Pro) forms.

Parvulin 17-catalyzed Tubulin Polymerization Is Regulated by Calmodulin in a Calcium-dependent Manner.

Recently we have shown that the peptidyl-prolyl cis/trans isomerase parvulin 17 (Par17) interacts with tubulin in a GTP-dependent manner, thereby promoting the formation of microtubules. Microtubule assembly is regulated by Ca(2+)-loaded calmodulin (Ca(2+)/CaM) both in the intact cell and under in vitro conditions via direct interaction with microtubule-associated proteins. Here we provide the first evidence that Ca(2+)/CaM interacts also with Par17 in a physiologically relevant way, thus preventing Par17-promoted microtubule assembly.

A streamlined method for preparing split intein for NMR study.

A protein ligase, intein, mediates a protein-splicing reaction. It can be split into two complementary fragments and reconstituted as a whole intein scaffold to perform protein trans-splicing. To understand the association of intein fragments and the splicing mechanism, it is necessary to produce a large quantity of split intein for structural study.

(13)C, (15)N and (1)H resonance assignments of receiver domain of ethylene receptor ETR1.

Ethylene plays versatile functions in regulating plant physiology. Although the high affinity ethylene receptor and its downstream regulators have been identified, the molecular recognition of the receptor interacting domains remains to be established. It has been speculated that the cytoplasmic signaling of the ethylene receptor is a two-component regulatory system involving the conserved receiver domain (RD).

Development of a mucin4-targeting SPIO contrast agent for effective detection of pancreatic tumor cells in vitro and in vivo.

In search of a unique and reliable contrast agent targeting pancreatic adenocarcinoma, new multifunctional nanoparticles (MnMEIO-silane-NH2-(MUC4)-mPEG NPs) were successfully developed in this study. Mucin4-expression levels were determined through different imaging studies in a panel of pancreatic tumor cells (HPAC, BxPC-3, and Panc-1) both in vitro and in vivo studies. The in vitro T2-weighted MR imaging study in HPAC and Panc-1 tumor cells treated with NPs showed -89.

NMR solution structure of a Chymotrypsin inhibitor from the Taiwan cobra Naja naja atra.

The Taiwan cobra (Naja naja atra) chymotrypsin inhibitor (NACI) consists of 57 amino acids and is related to other Kunitz-type inhibitors such as bovine pancreatic trypsin inhibitor (BPTI) and Bungarus fasciatus fraction IX (BF9), another chymotrypsin inhibitor. Here we present the solution structure of NACI. We determined the NMR structure of NACI with a root-mean-square deviation of 0.

Kinetics of transesterification of olive oil with methanol catalyzed by immobilized lipase derived from an isolated Burkholderia sp. strain.

This work was carried out to investigate the acyl migration phenomena which has been considered as the factor having significant impact on kinetics of transesterification of oils catalyzed by a Burkholderia lipase with 1,3-regioselectivity. Transesterification of olive oil with methanol catalyzed by the immobilized lipase produces various intermediates, including 1-monoglyceride, 2-monoglyceride, 1,2-diglyceride, and 1,3-diglyceride. Migration kinetics of fatty acid groups from sn-2 of 2-monoglyceride and 1,2-diglyceride to 1-monoglyceride and 1,3-diglyceride were investigated for the temperature range of 25-65°C.

The FKBP-type domain of the human aryl hydrocarbon receptor-interacting protein reveals an unusual Hsp90 interaction.

The aryl hydrocarbon receptor-interacting protein (AIP) has been predicted to consist of an N-terminal FKBP-type peptidyl-prolyl cis/trans isomerase (PPIase) domain and a C-terminal tetratricopeptide repeat (TPR) domain, as typically found in FK506-binding immunophilins. AIP, however, exhibited no inherent FK506 binding or PPIase activity. Alignment with the prototypic FKBP12 showed a high sequence homology but indicated inconsistencies with regard to the secondary structure prediction derived from chemical shift analysis of AIP(2-166).

¹H, ¹³C and ¹⁵N resonance assignments of human parvulin 17.

A 25-residue elongation at the N-terminus endows parvulin 17 (Par17) with altered functional properties compared to parvulin 14 (Par14), such as an enhanced influence on microtubule assembly. Therefore the three-dimensional structure of this N-terminal elongation is of particular interest. Here, we report the nearly complete (1)H, (13)C and (15)N chemical shift assignments of Par17.

Influence of ¹H chemical shift assignments of the interface residues on structure determinations of homodimeric proteins.

Homodimeric proteins pose a difficulty for NMR structure determination because the degeneracy of the chemical shifts in the two identical monomers implies an ambiguity in all assignments of distance restraints. For homodimeric proteins, residues involved in the interface between two monomers provide essential intermolecular NOEs. The structure determination of homodimeric proteins hence relies strongly on chemical shift assignments of these interface residues.

NMR assignments of the FKBP-type PPIase domain of the human aryl-hydrocarbon receptor-interacting protein (AIP).

The aryl-hydrocarbon receptor-interacting protein (AIP) interacts with several protein binding partners and has been associated with pituitary tumor development. Here, we report nearly complete (1)H, (13)C and (15)N chemical shift assignments for the N-terminal AIP(2-166) segment, which has been predicted to represent a FKBP-type PPIase domain. Sequence alignment with the prototypic FKBP12, however, reveals disagreements between the AIP chemical shift index consensus and the corresponding FKBP12 secondary structure elements.

Structural basis of the role of the NikA ribbon-helix-helix domain in initiating bacterial conjugation.

Conjugation is a fundamental process for the rapid evolution of bacteria, enabling them, for example, to adapt to various environmental conditions or to acquire multi-drug resistance. NikA is one of the relaxosomal proteins that initiate the intercellular transfer of the R64 conjugative plasmid with the P-type origin of transfer, oriT. The three-dimensional structure of the N-terminal 51 residue fragment of NikA, NikA(1-51), which binds to the 17-bp repeat A sequence in R64 oriT, was determined by NMR to be a homodimer composed of two identical ribbon-helix-helix (RHH) domains, which are commonly found in transcriptional repressors.

Solution structure of the extraterminal domain of the bromodomain-containing protein BRD4.

BRD4, which is a member of the BET (bromodomains and extraterminal) protein family, interacts preferentially with acetylated chromatin and possesses multiple cellular functions in meiosis, embryonic development, the cell cycle, and transcription. BRD4 and its family members contain two bromodomains known to bind acetylated lysine, and a conserved ET domain whose function is unclear. Here we show the solution structure of the ET domain of mouse BRD4, which provides the first three-dimensional structure of an ET domain in the BET family.

Structure of the subunit binding domain and dynamics of the di-domain region from the core of human branched chain alpha-ketoacid dehydrogenase complex.

The homo-24-meric dihydrolipoyl transacylase (E2) scaffold of the human branched-chain alpha-ketoacid dehydrogenase complex (BCKDC) contains the lipoyl-bearing domain (hbLBD), the subunit-binding domain (hbSBD) and the inner core domain that are linked to carry out E2 functions in substrate channeling and recognition. In this study, we employed NMR techniques to determine the structure of hbSBD and dynamics of several truncated constructs from the E2 component of the human BCKDC, including hbLBD (residues 1-84), hbSBD (residues 111-149), and a di-domain (hbDD) (residues 1-166) comprising hbLBD, hbSBD and the interdomain linker. The solution structure of hbSBD consists of two nearly parallel helices separated by a long loop, similar to the structures of the SBD isolated from other species, but it lacks the short 3(10) helix.

Solution structure of the 30 kDa polysulfide-sulfur transferase homodimer from Wolinella succinogenes.

The periplasmic polysulfide-sulfur transferase (Sud) protein encoded by Wolinella succinogenes is involved in oxidative phosphorylation with polysulfide-sulfur as a terminal electron acceptor. The polysulfide-sulfur is covalently bound to the catalytic Cys residue of the Sud protein and transferred to the active site of the membranous polysulfide reductase. The solution structure of the homodimeric Sud protein has been determined using heteronuclear multidimensional NMR techniques.