When diphtheria toxin encounters a low pH environment, the channel-forming T domain undergoes a poorly understood conformational change that allows for both its own membrane insertion and the translocation of the toxin's catalytic domain across the membrane. From the crystallographic structure of the water-soluble form of diphtheria toxin, a "double dagger" model was proposed in which two trans...

ab? h??tam muz?affar asfiz?r? (5th and 6th centuries a.h.), the great iranian mathematician, astronomers and scholors, was a contemporary of khayy?m. we don’t know much about his life excert what has been mentioned in some historians’ and scholars’, works. amony his most remarkable scientific achievements, we can mention his role in vernal equinox in order to modify and improve chronology and j...

the unique character of imam ali bin abi talib (a.s.) has occupied a high ranking position in shi'ite's literature since centuries. apart from the interest of arab shi'ite poets, we also find non-arabs who paid attention to imam ali's attributes and virtues, including mihiar al-dailami the persian who lived in buwaihid era.this study uses content analysis method aimed at stu...

the present article intends to study badr shakir al sayyab poetries in descriptive – analytical method by place semiotics which is paid attention by linguists. the outcome is that the study of place semiotics assists us to find the place beauties in sayyab poetries and discover the hidden treasures inside his poetry by the cities and villages he met his beloved. this article has been done based...

Herpes simplex virus 1 (HSV-1) ICP27 and ICP8 proteins have both been implicated in the transcription of late genes and regulation of viral gene expression. We showed previously that ICP27 and ICP8 associate with the RNAP II holoenzyme (Zhou and Knipe, J. Virol. 76, 5893-5904). Here, we demonstrate that ICP27 and ICP8 coprecipitate from lysates of HSV-1-infected HEp2 cells and from lysates of i...

BACKGROUND The detection of unknown mutations is important in research and medicine. For this purpose, a mismatch-specific endonuclease CEL I from celery has been established as a useful tool in high throughput projects. Previously, CEL I-like activities were described only in a variety of plants and could not be expressed in an active form in bacteria. RESULTS We describe expression of activ...

Precursor protein translocation across the Escherichia coli inner membrane is mediated by the translocase, which is composed of a heterotrimeric integral membrane protein complex with SecY, SecE, and SecG as subunits and peripherally bound SecA. Cross-linking experiments were conducted to study which proteins are associated with SecA in vivo. Formaldehyde treatment of intact cells results in th...

Bacterial cell surface display is a widely used technology for bioadsorption and for the development of a variety of screening systems. Magnetotactic bacteria are unique species of bacteria due to the presence of magnetic nanoparticles within them. These intracellular, nanosized (50 to 100 nm) magnetic nanoparticles enable the cells to migrate and be manipulated by magnetic force. In this work,...