Mechanism Sucrose-phosphate synthase

-


reaction scheme showing hexosyl group transfer udp-glucose fructose 6-phosphate.


in open conformation of h. orenii sps, fructose 6-phosphate forms hydrogen bonds gly-33 , gln-35 residues in domain while udp-glucose interacts b-domain. crystal structures studies reveal after binding, 2 domains twist narrow entrance of substrate binding cleft 20 Å 6 Å. in closed conformation, gly-34 residue of domain interacts udp-glucose , forces substrate adapt folded structure, facilitating donation of hexosyl group. after binding, fructose 6-phosphate interact udp via hydrogen bond, lowers activation energy of reaction , stabilizes transition state. finally, c1 atom of udp-glucose undergoes nucleophilic attack oxygen atom in fructose 6-phosphate, resulting in glucosyl group transfer fructose 6-phosphate. whether or not mechanism requires divalent ion unclear, failed attempts trap , detect presence of magnesium cation suggest mechanism metal ion independent.








Comments

Post a Comment

Popular posts from this blog

Life and work Ustad Mansur

-
tulip kashmir (c. 1610) mansur naqqash the year of mansur s birth unknown. name suffixed in miniatures naqqash, can refer artist, painter, or carver, indicating came family in artistic profession. single miniature showing babur meeting sister (folio 8, national museum) attributed mansur otherwise finds no mention in babur s memoirs (baburnama). associated other artists of period including basawan, miskina , nanha. during akbar s reign appears have been involved colourist in plates book of akbar (akbarnama) , name not mentioned abu l-fazl among list of artists. akbar followed principle artwork should include name of artist on margin. british museum s copy of akbarnama (1604) includes folios (35,110a,110b , 112a) name prefixed ustad (=master), indicating rise excellence. early works included parts of portraits , other scenes. earliest works made part of baburnama (1590–95) , of these assistant or colourist. veena-player (c. 1595) , coronation portrait of jahangir (c. 1605, made along
Read more

Kiev 35 mm cameras Kiev (brand)

-
kiev 4a rangefinder camera kiev 4 jupiter-8m lens , original camera case kiev produced several 35 mm film rangefinder cameras clones of pre-war contax ii , contax iii cameras, , range of 35mm slr cameras. after war had ended, soviet union demanded new sets of contax tools original toolmaker in dresden , ordered fair number of trial cameras made zeiss trademarks , coated lenses these 1946 in postwar east germany. successful, german instructors transferred kiev. missing specialists in few cases recruited in west germany. still available parts went in same direction. in fact, removing front of kiev ii cameras, 1 see metal stamped contax name, pressed out , re-stamped kiev. kiev 15 tee kiev 19 body kiev rangefinders retained same lens mount prewar contax rangefinders , lenses can interchanged. cameras went through few minor modifications become kiev iii , kiev 4. there kiev 5 modernized upper part integrated meter. attractive, though poorly made , unreliable, production terminated. other m
Read more

Types Stern

-
1 types 1.1 transom 1.2 elliptical 1.3 cruiser 1.4 others types transom 1. keel (light peach) 2. skeg (dark purple) 3. deadwood (olive drab) 4. stern post (forest green) 5. filling chock (bright yellow) 6. filling transoms (pale yellow-green) 7. wing transom (turquoise) 8. helm port (orange) 9. counter timbers (pale violet) 10. margin (indigo) 11. horn timber (green) 12. stern timbers (apricot) 13. side-counter timbers (pale yellow) 14. quarter-timbers (red) 15. fashion timber (fuchsia) 16. cant frames (blue) 17. square body frames (uncolored) in naval architecture, term transom has 2 meanings. first, transom can refer of individual beams run side-to-side or athwart hull @ point abaft fashion timber; second, transom can refer flat or curved surface panel of transom stern. in sense, transom stern product of use of series of transoms, , hence 2 terms have blended. the stern of classical sailing ship housed captain s quarters , became increasingly large , elaborate between 15th , 18th
Read more