Identification of a thiamin-dependent synthase in Escherichia coli required for the formation of the 1-deoxy-d-xylulose 5-phosphate precursor to isoprenoids, thiamin, and pyridoxol

In Escherichia coli, 1-deoxy-d-xylulose (or its 5-phosphate, DXP) is the biosynthetic precursor to isopentenyl diphosphate [Broers, S. T. J. (1994) Dissertation (Eidgenössische Technische Hochschule, Zürich)], thiamin, and pyridoxol [Himmeldirk, K., Kennedy, I. A., Hill, R. E., Sayer, B. G. & Spenser, I. D. (1996) Chem. Commun. 1187–1188]. Here we show that an open reading frame at 9 min on the chromosomal map of E. coli encodes an enzyme (deoxyxylulose-5-phosphate synthase, DXP synthase) that catalyzes a thiamin diphosphate-dependent acyloin condensation reaction between C atoms 2 and 3 of pyruvate and glyceraldehyde 3-phosphate to yield DXP. We have cloned and overexpressed the gene (dxs), and the enzyme was purified 17-fold to a specific activity of 0.85 unit/mg of protein. The reaction catalyzed by DXP synthase yielded exclusively DXP, which was characterized by 1H and 31P NMR spectroscopy. Although DXP synthase of E. coli shows sequence similarity to both transketolases and the E1 subunit of pyruvate dehydrogenase, it is a member of a distinct protein family, and putative DXP synthase sequences appear to be widespread in bacteria and plant chloroplasts.

Rapid acquisition of dendritic spines by visual thalamic neurons after blockade of N-methyl-D-aspartate receptors.

N-Methyl-D-aspartate (NMDA) receptors play an important role in the development of retinal axon arbors in the mammalian lateral geniculate nucleus (LGN). We investigated whether blockade of NMDA receptors in vivo or in vitro affects the dendritic development of LGN neurons during the period that retinogeniculate axons segregate into on-center and off-center sublaminae. Osmotic minipumps containing either the NMDA receptor antagonist D-2-amino-5-phosphonovaleric acid (D-APV) or saline were implanted in ferret kits at postnatal day 14. After 1 week, LGN neurons were intracellularly injected with Lucifer yellow. Infusion of D-APV in vivo led to an increase in the number of branch points and in the density of dendritic spines compared with age-matched normal or saline-treated animals. To examine the time course of spine formation, crystals of 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine perchlorate were placed in the LGN in brain slices from 14- to 18-day-old ferrets. Labeled LGN cell dendrites were imaged on-line in living slices by confocal microscopy, with slices maintained either in normal perfusion medium or with the addition of D-APV or NMDA to the medium. Addition of D-APV in vitro at doses specific for blocking NMDA receptors led to a > 6-fold net increase in spine density compared with control or NMDA-treated slices. Spines appeared within a few hours of NMDA receptor blockade, indicating a rapid local response by LGN cells in the absence of NMDA receptor activation. Thus, activity-dependent structural changes in postsynaptic cells act together with changes in presynaptic arbors to shape projection patterns and specific retinogeniculate connections.

Kitāb Shurūṭ al-imāmah / lil-Shaykh al-Imām Abū al-ʻAbbās Aḥmad ibn Ḥamzah al-Ramlī al-Anṣārī al-Shāfiʻī : manuscript, undated

Written in several hands, in one column, 23-24 lines per page, in black rubricated in red.

Kitāb Ghāyat al-maʼmūl fī sharḥ Zubdat al-uṣūl / al-matn li-Mawlānā al-Aqdas al-Shaykh Bahāʼ al-Dīn Khātimat al-mujtahidīn wa-al-sharḥ li-Sayyidinā al-Shaykh Muḥammad Jawād al-Kāẓimī : manuscript, 1651

Written in one column, 21 lines per pages, in black ink.

Kitāb iḥyāʾ al-qulūb sharḥ al-imām al-ʻārif billāh taʻālah ʻUmdat al-wāṣilīn wa-kaʻbat al-sālikīn yanbūʻ ʻilm al-ḥaqīqah wa-al-dīn mawlānā al-Shaykh ʻAbd al-Qādir al-Rāfiʻī al-Fārūqī al-Ṭarābulusī ʻalá ḥukum shaykhihi waliya Allāh ṣāḥib al-karāmāt al-ḍhāhirah wa-al-ishārāt al-bāhirah Sayyidī Maḥmūd al-Khallūtī.

Mode of access: Internet.

Hādhihi Ḥāshiyat al-ʻAllāmah al-fāḍil al-Shaykh Zayn al-Marṣafī ʻalá Sharḥ baytay al-Maqūlāt lil-ʻAllāmah al-Sujāʻī [microform]

Microfilm.

Sharḥ al-ʻAllāmah al-fāḍil al-insān al-kāmil ṣāḥib al-maʻārif al-bawāhir al-Shaykh Shihāb al-Dīn Aḥmad ibn ʻAbd al-Qādir al-maʻrūf bi-Bāʻashan [microform] : al-musammá bi-al-Bayān wa-al-mazīd : al-mushtamil ʻalá maʻānī al-tanzīh wa-ḥaqāʾiq al-tawḥīd ʻalá Uns al-waḥīd wa-nuzhat al-murīd min kalām al-ʻārif bi-mawlāhu Sayyidinā wa-Mawlānā Abī Madyan, raḥimahu Allāh taʻālá wa-arḍāh.

Microfilm.

Majmūʻah [microform] : Tuḥfah-ʾi Shāhjahānī : sharḥ-i risālah-ʾi Ādāb-i Muṭālaʻah, ḥall-i tarkīb-i manṭiq maʻa munhayāt-i ʻajībah, sharḥ-i Tahẕīb bi-ḥavāshī-i jadīdah /

Microfilm.

Tuḥfah-ʾi Shāhjahānī [microform] : sharḥ-i risālah-ʾi Ādāb-i muṭālaʻah, ḥall-i tarkīb-i manṭiq maʻa munhayāt-i ʻajībah, sharḥ-i Tahẕīb bi-ḥawāshī-i jadīdah /

Microfilm.

Hādhā nuskhah tarīfah wa-risālah sharīfah al-musammāh bi-Tajrīd al-uṣūl [microform] /

Microfilm.

Original journals of the Lewis and Clark Expedition, 1804-1806; printed from the original manuscripts in the library of the American Philosophical Society and by direction of its committee on historical documents, together with manuscript material of Lewis and Clark from other sources, including note-books, letters, maps, etc., and the journals of Charles Floyd and Joseph Whitehouse, now for the first time published in full and exactly as written.

Vol. 8 has title: Atlas accompanying the original journals of the Lewis and Clark Expedition, 1804-1806, being facsimile reproductions of maps, chiefly by William Clark ... Now for the first time published, from the original manuscripts ... together with a modern map of the route ...

The tragedy of Jane Shore. : Written in imitation of Shakespear's style. /

Head- and tail-pieces; initials; title vignette.

The Dabistan, or, School of manners /

Includes index.

Chrestomathiam Hieronymianam continentem /

Includes bibliographical references.

A sketch of the life, last sickness, and death of Mrs. Mary Jane Grosvenor /

Appendix contains brief sketch of the author.