Nucleotide sequence of the celC gene encoding endoglucanase C of Clostridium thermocellum

The nucleotide sequence of the cellulase gene celC, encoding endoglucanase C of Clostridium thermocellum, has been determined. The coding region of 1032 bp was identified by comparison with the N-terminal amino acid (aa) sequence of endoglucanase C purified from Escherichia coli. The ATG start codon is preceded by an AGGAGG sequence typical of ribosome-binding sites in Gram-positive bacteria. The derived amino acid sequence corresponds to a protein of Mr 40,439. Amino acid analysis and apparent Mr of endoglucanase C are consistent with the amino acid sequence as derived from the DNA sequencing data. A proposed N-terminal 21-aa residue leader (signal) sequence differs from other prokaryotic signal peptides and is non-functional in E. coli. Most of the protein bears no resemblance to the endoglucanases A, B, and D of the same organism. However, a short region of homology between endoglucanases A and C was identified, which is similar to the established active sites of lysozymes and to related sequences of fungal cellulases.     

Activity of alkaline phosphatase in uterine flushings of dairy cows affected with ovarian cysts or endometritis

Both uterine horns of 14 dairy cows with ovarian follicular cysts, and four animals affected with purulent endometritis were flushed via catheter using 30 ml phosphate buffered saline, following evisceration at a local abattori. Activity in the flushing media of alkaline phosphatase (ALP) and aspartate aminotransferase (GOT) were examined. Ovaries were prepared for light microscopy. Amount and morphological integrity of luteinized tissue found on the ovaries were reflected by correspondent levels in ALP activity, which was higher in the media taken from the ipsilateral to the luteal tissue situated uterine horns (651 +/- 228 vs 244 +/- 62 u/l, n = 3). Only cows having relatively large amounts of luteal tissue on the cystic ovaries (as in luteinized follicular cysts) exhibited very high ALP activity in uterine flushings (2693 +/- 1348 u/l, n = 2). Results suggest the existence of local relationships between luteal tissue in the ovary and the ipsilateral uterine horn in cows with ovarian follicular cysts.     

Isolation of aClostridium thermocellum gene encoding a thermostable β-1, 3-glucanase (laminarinase)

Summary AClostridium thermocellum gene directing the synthesis of a thermostable -glucanase was localized on a 1.9-kb DNA fragment by subcloning intoEscherichia coli plasmid vectors. The enzyme was highly efficient in degrading glucans with alternating -1, 3- and -1,4-linkages such as lichenan and barley glucan. It was also active towards the -1, 3-glucan laminarin, but lacked activity on cellulosic substrates and -glucans. The enzyme was therefore classified as -1, 3-glucanase (laminarinase) and the corresponding gene was designatedlicA. With barley -glucan as substrate the enzyme had a pH optimum around pH 6.5 and a temperature optimum at 65°C. It was stable for several hours at 60°C in the absence of substrate.     

Structure and function of ferredoxin-NADP+-oxidoreductase

The redox-enzyme ferredoxin-NADP-oxidoreductase has been shown to be activated by light and inactivated in the dark. This review will summarize recent data concerning the biochemical characterization of the enzyme compared to its in-vivo activation. Further-more the mechanism of this activation process is discussed as a conformational change caused by the light-driven proton gradient.Abbreviations cyt cytochrome - fd ferredoxin - FNR1 large form of ferredoxin-NADP-oxidoreductase - FNRox oxidized FNR - FNRred reduced FNR - FNRs small form of FNR - FNRsq FNR-semiquinone     

Organisation and expression of a wound/ripening-related small multigene family from tomato

cDNA clones derived from a ripe tomato fruit cDNA library were used to investigate changes in the abundance of specific mRNAs in ripening fruit and wounded leaves. mRNAs related to one cDNA clone (pTOM 13) were expressed in both situations. This clone was used to identify homologous sequences in a tomato genomic library. Three groups of related clones that hybridised to the pTOM 13 cDNA insert were identified and subcloned into plasmid vectors. Genomic Southern analysis of tomato DNA using gene-specific DNA fragments isolated from the subcloned DNAs indicated that all pTOM 13 closely related genes had been isolated. RNA dot blot analysis with these DNA fragments as probes indicated differential expression of this small multigene family in leaves and fruit.     

Recovery of metals from acid waste water by Cyanidium caldarium

Summary Cyanidium caldarium grows in acid water obtained from a bacterial leaching procedure and the alga is capable of precipitating metals from the solution. This study demonstrates that changes in culture and oxidation-reduction conditions may result in a different bioaccumulation of metals.     

Partial purification and characterization of a cellular protein that binds to the SV40 core origin of DNA replication

A monkey cell factor that interacts specifically with double- and single-stranded DNA sequences in the early domain of the simian virus 40 (SV40) core origin of replication was identified using gel-retention assays. The protein was enriched over 1200-fold using ion-exchange and affinity chromatography on single-strand DNA cellulose. Binding of protein to mutant origin DNA restriction fragments was correlated with replication activity of the mutant DNAs. Exonuclease footprint experiments on single-stranded DNA revealed prominent pause sites in the early domain of the core origin. The results suggest that this cellular protein may be involved in SV40 DNA replication.     

Orientation of Dunnocks (Prunella modularis) at Sunset

To find out the relative importance of the geomagnetic and solar cues for the orientation at the time of sunset, dunnocks were tested outdoors during the spring migration periods of 1982 and 1983. Experimental magnetic fields were produced by Helmholtz coils. In the various magnetic conditions, the following results were obtained:

• 1 In the local geomagnetic field, the dunnocks oriented in a seasonally appropriate northerly direction.
• 2 In a magnetic field the north of which was shifted 120° clock-wise to ESE, the birds showed a corresponding shift in their orientation.
• 3 In a vertical magnetic field without meaningful directional information, birds previously tested in either the local geomagnetic field or the shifted magnetic field now displayed axially bimodal orientation, with the axes of the two groups differing.

These findings indicate that for migratory dunnocks, the magnetic field plays a dominant role in determining their orientation at the time of sunset, and that magnetic information may affect the dunnocks' response to other directional, presumably solar cues as well.