Die Greizer Mundart

Von L. Hertel

Verteilung und Zunahme der Bevölkerung im Thüringerwald nach Höhenstufen

Von Dr. Ludwig Klinger

Aufruf

Kolonialkriegerdank e.V. Herzog Johann Albrecht zu Mecklenburg ; [Georg] Freiherr von Gayl

Neues israelitisches Gebetbuch für die Wochentage, Sabbathe und alle Feste zum Gebrauche während des Gottesdienstes und bei der häuslichen Andacht

Von Ludwig Philippson

Den braven Studenten : Einen Gruße Dir edle Jugend ... ; Wien, am 15. März 1848

von Ludwig Bowitsch

Warum trauert das Vaterland? : eine Predigt, gehalten bei dem Trauergottesdienste am 14. August 1859 wegen Ablebens Sr. Maj. des hochseligen Königs Oscar I. gesegneten Andenkens

von Dr. L. Lewysohn

Photographisches Lexicon : alphabetisches Nachschlagebuch für den praktischen Photographen sowie für Maler, Chemiker, Techniker, Optiker etc., auf Grund der neuesten Fortschritte ; unter Berücksichtigung der neuesten deutschen, englischen und französischen Literatur sowie eigener Erfahrungen

hrsg. von Julius Schnauss

Ordo historiae Iuris Civilis praelectionibus institutionum praemissus

Índice

In Vitro Studies with Purified Components Reveal Signal Recognition Particle (SRP) and SecA/SecB as Constituents of Two Independent Protein-targeting Pathways of Escherichia coli

The molecular requirements for the translocation of secretory proteins across, and the integration of membrane proteins into, the plasma membrane of Escherichia coli were compared. This was achieved in a novel cell-free system from E. coli which, by extensive subfractionation, was simultaneously rendered deficient in SecA/SecB and the signal recognition particle (SRP) components, Ffh (P48), 4.5S RNA, and FtsY. The integration of two membrane proteins into inside-out plasma membrane vesicles of E. coli required all three SRP components and could not be driven by SecA, SecB, and ΔμH+. In contrast, these were the only components required for the translocation of secretory proteins into membrane vesicles, a process in which the SRP components were completely inactive. Our results, while confirming previous in vivo studies, provide the first in vitro evidence for the dependence of the integration of polytopic inner membrane proteins on SRP in E. coli. Furthermore, they suggest that SRP and SecA/SecB have different substrate specificities resulting in two separate targeting mechanisms for membrane and secretory proteins in E. coli. Both targeting pathways intersect at the translocation pore because they are equally affected by a blocked translocation channel.

Expression of Tobacco Carbonic Anhydrase in the C4 Dicot Flaveria bidentis Leads to Increased Leakiness of the Bundle Sheath and a Defective CO2-Concentrating Mechanism

Flaveria bidentis (L.) Kuntze, a C4 dicot, was genetically transformed with a construct encoding the mature form of tobacco (Nicotiana tabacum L.) carbonic anhydrase (CA) under the control of a strong constitutive promoter. Expression of the tobacco CA was detected in transformant whole-leaf and bundle-sheath cell (bsc) extracts by immunoblot analysis. Whole-leaf extracts from two CA-transformed lines demonstrated 10% to 50% more CA activity on a ribulose-1,5-bisphosphate carboxylase/oxygenase-site basis than the extracts from transformed, nonexpressing control plants, whereas 3 to 5 times more activity was measured in CA transformant bsc extracts. This increased CA activity resulted in plants with moderately reduced rates of CO2 assimilation (A) and an appreciable increase in C isotope discrimination compared with the controls. With increasing O2 concentrations up to 40% (v/v), a greater inhibition of A was found for transformants than for wild-type plants; however, the quantum yield of photosystem II did not differ appreciably between these two groups over the O2 levels tested. The quantum yield of photosystem II-to-A ratio suggested that at higher O2 concentrations, the transformants had increased rates of photorespiration. Thus, the expression of active tobacco CA in the cytosol of F. bidentis bsc and mesophyll cells perturbed the C4 CO2-concentrating mechanism by increasing the permeability of the bsc to inorganic C and, thereby, decreasing the availability of CO2 for photosynthetic assimilation by ribulose-1,5-bisphosphate carboxylase/oxygenase.

Gerard David und seine Schule.

Full name: Hans Eberhard Freiherr von Bodenhausen-Degener.

Wissen und arbeit, ihre sociale bedeuting.

Mode of access: Internet.

Oberbayerische Lieder mit ihren Singweisen, im Auftrage und mit Untersetzung Seiner Majestät des Königs für das bayerische Gebirgsvolk gesammelt und hrsg.

Principally melodies with words; a few for 2-3 voices.