Characterization of recombinant phytochrome from the cyanobacterium  Synechocystis

Abstract

following correction should be noted. Due to an editorial change at PNAS, the meaning of the last sentence on page 14046 was altered. The sentence originally read as follows: On the other hand, this structure does not reproduce the pharmacological properties of either P or Q channel exactly, as the ID 50 to sFTX and -Aga IVA for P-type channels is lower than for the ␣1A, ␣2␦, ␤Ib channels in HEK cells.Neurobiology. In the article "The synthesis of ATP by glycolytic enzymes in the postsynaptic density and the effect of endogenously generated nitric oxide" Kuo Wu, Chiye Aoki, Alice Elste, Adrienne A. Rogalski-Wilk, and Philip Siekevitz, which appeared in number 24, November 25, 1997, of Proc. Natl. Acad. Sci. USA (94,(13273)(13274)(13275)(13276)(13277)(13278), the quality of the reproduction of Fig. 2A was poor. The figure and its legend are shown below:Biochemistry. In the article "KSR stimulates Raf-1 activity in a kinase-independent manner" by Neil R. Michaud, Marc Therrien, Angela Cacace, Lisa C. Edsall, Sarah Spiegel, Gerald M. Rubin, and Deborah K. Morrison, which appeared in number 24, November 25, 1997, of Proc. Natl. Acad. Sci. USA (94,(12792)(12793)(12794)(12795)(12796), the following correction should be noted.Due to a printer's error, background was incorrectly added to (50 g) and 100 g each of the other fractions, in 100 l final volume, including whole homogenate (H), synaptosomes (Syn), synaptic plasma membranes (SPM), and crude synaptic vesicles (CSV), were incubated at 37°C for 15 min. NAD incorporation was performed in the absence (Ϫ) or presence (ϩ) of SNP as exogenous source of NO. The mixtures were subjected to SDS͞PAGE and then autoradiography. (B) Western blot analysis of the G3PD in the subcellular fractions. To confirm that the radioactive protein in the subcellular fractions was indeed G3PD, Western blot analysis was performed by using specific anti-G3PD antibodies as described.

The pair of bacteriophytochromes from Agrobacterium tumefaciens are histidine kinases with opposing photobiological properties

“…3). Like previous observations with phys and Cphs (18,19), AtBphP1 rapidly assembled with BV to generate a Pr conformation that was highly stable even after prolonged incubations in the dark. AtBphP2 also rapidly assembled with BV to generate Pr, but this form was transient and immediately began converting nonphotochemcially to Pfr (t 1/2 Ϸ 15 min) (Fig.…”

“…We note that AtBphP2, as compared with other phys, has a substantially reduced Pr absorbance at its peak at 698 nm versus its Soret peak at Ϸ400 nm. Such a reduction is characteristic of bilins that assume a more helical conformation within their protein binding pockets (19), implying that the molecular environment of BV when bound to AtBphP1 and AtBphP2 differs. Further support that the chromophore-binding pockets are different comes from attempts to assemble the AtBphPs with PCB.…”

Phytochrome from Agrobacterium tumefaciens has unusual spectral properties and reveals an N-terminal chromophore attachment site

“…Database searches were performed on National Center for Biotechnology Information (NCBI) BLASTP (http:͞͞ncbi.nlm.nih.gov); the Agrobacterium phytochrome homologues (Agp1 and Agp2) were found with Cph1 as template (17). Both Agrobacterium sequences are already mentioned in an earlier publication (11).…”

“…A comparable darkreversion has so far not been found in bacterial phytochromes. Cph1 of Synechocystis (17) and CphA of Calothrix (18) have a stable Pfr form; reports on other bacterial orthologs are missing so far.…”

Ultrafast excited-state isomerization in phytochrome revealed by femtosecond stimulated Raman spectroscopy

“…The two-state model for P r * decay has also received support from ultrafast transient absorption measurements on the plant phytochrome phyA, the cyanobacterial phytochrome Cph1, and the bacteriophytochrome Agp1, all of which exhibit two excited-state lifetimes characterized by a short (5-16 ps) and a long (25-40 ps) time constant (8,10,11). Despite the kinetic insight of these transient electronic spectroscopic studies, these techniques do not establish when the double bond isomerization occurs, nor do they resolve the molecular basis for the low P r -to-P fr photochemical quantum yields (7-16%) (12,13).…”