Protonatable residues at the cytoplasmic end of transmembrane helix-2 in the signal transducer HtrI control photochemistry and function of sensory rhodopsin I.

Neutral residue replacements were made of 21 acidic and basic residues within the N-terminal half of the Halobacterium salinarium signal transducer HtrI [the halobacterial transducer for sensory rhodopsin I (SRI)] by site-specific mutagenesis. The replacements are all within the region of HtrI that we previously concluded from deletion analysis to contain sites of interaction with the phototaxis receptor SRI. Immunoblotting shows plasmid expression of the htrI-sopI operon containing the mutations produces SRI and mutant HtrI in cells at near wild-type levels. Six of the HtrI mutations perturb photochemical kinetics of SRI and one reverses the phototaxis response. Substitution with neutral amino acids of Asp-86, Glu-87, and Glu-108 accelerate, and of Arg-70, Arg-84, and Arg-99 retard, the SRI photocycle. Opposite effects on photocycle rate cancel in double mutants containing one replaced acidic and one replaced basic residue. Laser flash spectroscopy shows the kinetic perturbations are due to alteration of the rate of reprotonation of the retinylidene Schiff base. All of these mutations permit normal attractant and repellent signaling. On the other hand, the substitution of Glu-56 with the isosteric glutamine converts the normally attractant effect of orange light to a repellent signal in vivo at neutral pH (inverted signaling). Low pH corrects the inversion due to Glu-56 -> Gln and the apparent pK of the inversion is increased when arginine is substituted at position 56. The results indicate that the cytoplasmic end of transmembrane helix-2 and the initial part of the cytoplasmic domain contain interaction sites with SRI. To explain these and previous results, we propose a model in which (i) the HtrI region identified here forms part of an electrostatic bonding network that extends through the SRI protein and includes its photoactive site; (ii) alteration of this network by photoisomerization-induced Schiff base deprotonation and reprotonation shifts HtrI between attractant and repellent conformations; and (iii) HtrI mutations and extracellular pH alter the equilibrium ratios of these conformations.

The photoreceptor sensory rhodopsin I as a two-photon-driven proton pump.

Proton translocation experiments with intact cells of Halobacterium salinarium overproducing sensory rhodopsin I (SRI) revealed transport activity of SRI in a two-photon process. The vectoriality of proton translocation depends on pH, being outwardly directed above, and inwardly directed below, pH 5.7. Activation of the transport cycle requires excitation of the initial dark state of SRI, SRI590, to form the intermediate SRI380. Action spectra identify the photocycle intermediates SRI380 and SRI520 as the two photochemically reactive species in the outwardly directed transport process. As shown by flash photolysis experiments, SRI520 undergoes a so-far unknown photochemical reaction to SRI380 with a half-time of <200 micros. Mutation of SRI residue Asp-76, the residue which is equivalent to the proton acceptor Asp-85 in bacteriorhodopsin, to asparagine leads to inactivation of proton translocation. This demonstrates that the underlying mechanisms of proton transport in both retinal proteins share similar features. However, SRI is to our knowledge the first case where photochemical reactions between two thermally unstable photoproducts of a retinal protein constitute a catalytic ion transport cycle.

Annals of the Royal Botanic Gardens, Peradeniya.

4, 1907-10

The fishes of India : being a natural history of the fishes known to inhabit the seas and fresh waters of India, Burma and Ceylon / by Francis Day.

text

The fishes of India : being a natural history of the fishes known to inhabit the seas and fresh waters of India, Burma and Ceylon / by Francis Day.

suppl.

India, 1788 (Image 1 of 4) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: A map of Hindoostan, or the Mogul Empire : from the latest authorities. Inscribed to Sir Joseph Banks Bart., President of the Royal Society & c., & c. by his much obliged & faithful friend and servant, J. Rennell, 1st Jany. 1788 ; the map engraved by I. Phillips & W. Harrison ; writing by T. Harmar. It was published by James Rennell in 1788. Scale [ca. 1:3,000,000]. This layer is image 1 of 4 total images of the four sheet source map, covering the southwest portion of the map. Covers primarily India and adjacent portions of Asia.The image inside the map neatline is georeferenced to the surface of the earth and fit to the Asia North Lambert Conformal Conic coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, roads, territorial boundaries, shoreline features, and more. Relief shown pictorially. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

India, 1788 (Image 2 of 4) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: A map of Hindoostan, or the Mogul Empire : from the latest authorities. Inscribed to Sir Joseph Banks Bart., President of the Royal Society & c., & c. by his much obliged & faithful friend and servant, J. Rennell, 1st Jany. 1788 ; the map engraved by I. Phillips & W. Harrison ; writing by T. Harmar. It was published by James Rennell in 1788. Scale [ca. 1:3,000,000]. This layer is image 2 of 4 total images of the four sheet source map, covering the southeast portion of the map. Covers primarily India and adjacent portions of Asia.The image inside the map neatline is georeferenced to the surface of the earth and fit to the Asia North Lambert Conformal Conic coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, roads, territorial boundaries, shoreline features, and more. Relief shown pictorially. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

India, 1804 (Sheet 4 of 6) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: To Mark Wood Esq., M.P. colonel of the Army in India, late Chief Engineer and Surveyor General, Bengal, this map of India, compiled from various interesting and valuable materials, is inscribed in grateful testimony of his liberal communications, by ... A. Arrowsmith ; George Allen sculp. It was published by A. Arrowsmith in 1804. Scale [ca. 1:1,800,000]. This layer is image 4 of 6 total images of the six sheet source map, representing the southwest portion of the map. Covers primarily India and adjacent portions of Asia.The image inside the map neatline is georeferenced to the surface of the earth and fit to the Asia North Lambert Conformal Conic coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, roads, territorial boundaries, shoreline features, and more. Relief shown by hachures. Includes also notes on the navigability of rivers.This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

India, 1804 (Image 6 of 6) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: To Mark Wood Esq., M.P. colonel of the Army in India, late Chief Engineer and Surveyor General, Bengal, this map of India, compiled from various interesting and valuable materials, is inscribed in grateful testimony of his liberal communications, by ... A. Arrowsmith ; George Allen sculp. It was published by A. Arrowsmith in 1804. Scale [ca. 1:1,800,000]. This layer is image 6 of 6 total images of the six sheet source map, representing the southeast portion of the map. Covers primarily India and adjacent portions of Asia.The image inside the map neatline is georeferenced to the surface of the earth and fit to the Asia North Lambert Conformal Conic coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, roads, territorial boundaries, shoreline features, and more. Relief shown by hachures. Includes also notes on the navigability of rivers.This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

Indian Ocean Region, ca. 1690 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Nova tabula Indiae Orientalis. It was published by Carolus Allard excudit, between 1690 and 1710. Scale [ca. 1:5,500,000]. Covers the Indian Ocean Region. Map in Latin. The image inside the map neatline is georeferenced to the surface of the earth and fit to the World Miller Cylindrical projected coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, roads, cities and other human settlements, territorial boundaries, shoreline features, and more. Relief shown pictorially.This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

India & South Asia, 1752 (Image 1 of 2) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Carte de l'Inde : dressée pour la Compagnie des Indes, par le Sr. d'Anville, Sécrétaire de S.A.S. Mgr. le Duc d'Orleans ; [engraved by] Guill.' de-la-Haye. It was published by Jean Baptiste Bourguignon d'Anville in November 1752. Scale [ca. 1:3,100,000]. This layer is image 1 of 2 total images of the two sheet source map, representing the northern portion of the map. Covers India and portions of South Asia. Map in French. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Kalianpur 1975 India Zone III projected coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, roads, shoreline features, and more. Relief shown pictorially. Includes insets: Negraïs -- Rivière d'Aracan -- Riv. de Sirian -- Archipel de Merghi -- Environs de Junk Selon -- Environs d'Ashem -- Entréé du Gange -- Environs de Goa. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

India & South Asia, 1752 (Image 2 of 2) (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Carte de l'Inde : dressée pour la Compagnie des Indes, par le Sr. d'Anville, Sécrétaire de S.A.S. Mgr. le Duc d'Orleans ; [engraved by] Guill.' de-la-Haye. It was published by Jean Baptiste Bourguignon d'Anville in November 1752. Scale [ca. 1:3,100,000]. This layer is image 2 of 2 total images of the two sheet source map, representing the southern portion of the map. Covers India and portions of South Asia. Map in French. The image inside the map neatline is georeferenced to the surface of the earth and fit to the Kalianpur 1975 India Zone III projected coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, cities and other human settlements, roads, shoreline features, and more. Relief shown pictorially. Includes insets: Negraïs -- Rivière d'Aracan -- Riv. de Sirian -- Archipel de Merghi -- Environs de Junk Selon -- Environs d'Ashem -- Entréé du Gange -- Environs de Goa. This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.