Dr. Adolf Sidon : zu seinem 70. Geburtstag

Ludwig Blau

Waisenhausdirektor Dr. Deutsch in Fürth zu seinem 70. Geburtstag

D. J. Bamberger

Moses Marx zum 70. Geburtstag

M. Adler

Kommerzienrat Ludwig Rosenzweigs 70. Geburtstag

E. D.

Armin Vámbéry : (zu seinem 70. Geburtstage: 19. März)

Leopold Katscher

An analysis of the function of region 1.2 of the primary sigma factor, sigma 70, from Escherichia coli

The sigma (σ) subunit of eubacterial RNA polymerase is required for recognition of and transcription initiation from promoter DNA sequences. One family of sigma factors includes those related to the primary sigma factor from E. coli, σ70. Members of the σ70 family have four highly conserved domains, of which regions 2 through 4 are present in all members. Region 1 can be subdivided into regions 1.1 and 1.2. Region 1.1 affects DNA binding by σ 70 alone, as well as transcription initiation by holoenzyme. Region 1.2, present and highly conserved in most sigma factors, has not yet been assigned a putative function, although previous work demonstrated that it is not required for either association with the core subunits of RNA polymerase or promoter specific binding by holoenzyme. This study primarily investigates the functional role of region 1.2 during transcription initiation. In vivo and in vitro characterization of thirty-two single amino acid substitutions targeted to region 1.2 of E. coli σ70 as well as a deletion of region 1.2, revealed that mutations in region 1.2 can affect promoter binding, open complex formation, initiated complex formation, and the transition from abortive transcription to elongation. The relative degree of solvent exposure of several positions in region 1.2 has been determined, with positions 116 and 122 likely to be located near the surface of σ70. ^ During the course of this study, the existence of two “wild type” variants of E. coli σ70 was discovered. The identity of amino acid 149 has been reported variably as either arginine or aspartic acid in published articles and in online databases. In vivo and in vitro characterization of the two reported variations of E. coli σ70 (N149 and D149) has determined that the two variants are functionally equivalent. However, in vivo and in vitro characterization of single amino acid substitutions and a region 1.2 deletion in the context of each variant background revealed that the behavior of some mutations are greatly affected by the identity of amino acid 149. ^

Dimitra A. Stourdza : (zu seinem 70. Geburtstage)

Th. Plebe

Anteilnahme der physischen Welt an den Schicksalen der Menschen : Herrn Prof. Dr. Brann zum 70. Geburtstag

Viktor Aptowitzer

Anteilnahme der physischen Welt an den Schicksalen der Menschen : Herrn Prof. Dr. Brann zum 70. Geburtstage

Viktor Aptowitzer

Einzelbemerkungen zur Lieferung 3 - 6 der Holtzmannschen Mischna-Ausgabe [Rezension] : (Fortsetzung von Jahrg. 1918, S. 70-75)

Viktor Aptowitzer

Zu Jeruschalmi Berachoth 6 a, 42 und Abodah Zarah 43 b, 70

Viktor Aptowitzer

Verzeichnis der von Markus Brann verfaßten Schriften und Abhandlungen : dem Freunde zum 70. Geburtstag gewidmet

Aaron Freimann

Anteilnahme der physischen Welt an den Schicksalen der Menschen : Hernn Prof. Dr. Brann zum 70. Geburtstag

Viktor Aptowitzer