Cloning, Mapping, and Expression of Two Novel Actin Genes, Actin-like-7A (ACTL7A) and Actin-like-7B (ACTL7B), from the Familial Dysautonomia Candidate Region on 9q31

Two novel human actin-like genes, ACTL7A and ACTL7B, were identified by cDNA selection and direct genomic sequencing from the familial dysautonomia candidate region on 9q31. ACTL7A encodes a 435-amino-acid protein (predicted molecular mass 48.6 kDa) and ACTL7B encodes a 415-amino-acid protein (predicted molecular mass 45.2 kDa) that show greater than 65% amino acid identity to each other. Genomic analysis revealed ACTL7A and ACTL7B to be intronless genes contained on a common 8-kb HindIII fragment in a “head-to-head” orientation. The murine homologues were cloned and mapped by linkage analysis to mouse chromosome 4 in a region of gene order conserved with human chromosome 9q31. No recombinants were observed between the two genes, indicating a close physical proximity in mouse. ACTL7A is expressed in a wide variety of adult tissues, while the ACTL7B message was detected only in the testis and, to a lesser extent, in the prostate. No coding sequence mutations, genomic rearrangements, or differences in expression were detected for either gene in familial dysautonomia patients.     

Whole life considerations in it procurement

Goal, Scope and Background  

Waste associated with the manufacture, use, and disposal of electronic products, or e-waste, is a growing threat to the environment. IT procurement professionals can have a positive affect against that threat through careful consideration of the environmental awareness of their vendors.     

The structure and function of the cytochrome <Emphasis Type="Italic">c</Emphasis><Subscript>2</Subscript>: reaction center electron transfer complex from <Emphasis Type="Italic">Rhodobacter sphaeroides</Emphasis>

In the photosynthetic bacterium, Rhodobacter sphaeroides, the mobile electron carrier, cytochrome c₂ (cyt c₂) transfers an electron from reduced heme to the photooxidized bacteriochlorophyll dimer in the membrane bound reaction center (RC) as part of the light induced cyclic electron transfer chain. A complex between these two proteins that is active in electron transfer has been crystallized and its structure determined by X-ray diffraction. The structure of the cyt:RC complex shows the cyt c₂ (cyt c₂) positioned at the center of the periplasmic surface of the RC. The exposed heme edge from cyt c₂ is in close tunneling contact with the electron acceptor through an intervening bridging residue, Tyr L162 located on the RC surface directly above the bacteriochlorophyll dimer. The binding interface between the two proteins can be divided into two regions: a short-range interaction domain and a long-range interaction domain. The short-range domain includes residues immediately surrounding the tunneling contact region around the heme and Tyr L162 that display close intermolecular contacts optimized for electron transfer. These include a small number of hydrophobic interactions, hydrogen bonds and a pi-cation interaction. The long-range interaction domain consists of solvated complementary charged residues; positively charged residues from the cyt and negatively charged residues from the RC that provide long range electrostatic interactions that can steer the two proteins into position for rapid association.     

Characterization of a Highly Purified, Fully Active, Crystallizable RC–LH1–PufX Core Complex from Rhodobacter sphaeroides

Photosynthetic complexes in bacteria absorb light and undergo photochemistry with high quantum efficiency. We describe the isolation of a highly purified, active, reaction center-light-harvesting 1–PufX complex (RC–LH1–PufX core complex) from a strain of the photosynthetic bacterium, Rhodobacter sphaeroides, which lacks the light-harvesting 2 (LH2) and contains a 6 histidine tag on the H subunit of the RC. The complex was solubilized with diheptanoyl-sn-glycero-3-phosphocholine (DHPC), and purified by Ni-affinity, size-exclusion and ion-exchange chromatography in dodecyl maltoside. SDS-PAGE analysis shows the complex to be highly purified. The quantum efficiency was determined by measuring the charge separation (DQ_A → D⁺Q_A^-) in the RC as a function of light intensity. The RC–LH1–PufX complex had a quantum efficiency of 0.95 ± 0.05, indicating full activity. The stoichiometry of LH1 subunits per RC was determined by two independent methods: (i) solvent extraction and absorbance spectroscopy of bacteriochlorophyll, and (ii) density scanning of the SDS-PAGE bands. The average stoichiometry from the two measurements was 13.3 ± 0.9 LH1/RC. The presence of PufX was observed in SDS-PAGE gels at a stoichiometry of 1.1 ± 0.1/RC. Crystals of the core complex have been obtained which diffract X-rays to 12 Å. A preliminary analysis of the space group and unit cell analysis indicated a P1 space group with unit cell dimensions of a = 76.3 Å, b = 137.2 Å, c = 137.5 Å; α = 60.0°, β = 89.95°, γ =90.02°.     

The role of cytokines in liver failure and regeneration: potential new molecular therapies

The liver is a unique organ, and first in line, the hepatocytes encounter the potential to proliferate during cell mass loss. This phenomenon is tightly controlled and resembles in some way the embryonal co-inhabitant cell lineage of the liver, the embryonic hematopoietic system. Interestingly, both the liver and hematopoietic cell proliferation and growth are controlled by various growth factors and cytokines. IL-6 and its signaling cascade inside the cells through STAT3 are both significantly important for liver regeneration as well as for hematopoietic cell proliferation. The process of liver regeneration is very complex and is dependent on the etiology and extent of liver damage and the genetic background. In this review we will initially describe the clinical relevant condition, portraying a number of available animal models with an emphasis on the relevance of each one to the human condition of fulminant hepatic failure (FHF). The discussion will then be focused on the role of cytokines in liver failure and regeneration, and suggest potential new therapeutic modalities for FHF. The recent findings on the role of IL-6 in liver regeneration and the activity of the designer IL-6/sIL-6R fusion protein, hyper-IL-6, in particular, suggest that this molecule could significantly enhance liver regeneration in humans, and as such could be a useful treatment for FHF in patients.     

Crystallization and preliminary X-ray investigation of lipoxygenase-3 from soybeans.

Soybean lipoxygenase-3 has been crystallized by the vapor diffusion method in 16-20% polyethylene glycol (average M(r), 3,400), 0.2 M sodium acetate buffer, pH 5.7, at 21 degrees C, at a protein concentration of 8-15 mg/mL. The crystals, which diffract to 3-A spacings, belong to the monoclinic space group C2. Cell constants are a = 111.9, b = 136.4, and c = 61.6 A and beta = 95.7 degrees. The calculated value of Matthews's constant, Vm = 2.48 A3/kDa, is consistent with the presence of one molecule of lipoxygenase per crystallographic asymmetric unit (Z = 4).