Neutron crystallographic study of heterotrimeric glutamine amidotransferase CAB.
Acta Crystallogr F Struct Biol Commun
; 75(Pt 3): 193-196, 2019 Mar 01.
Article
in En
| MEDLINE
| ID: mdl-30839294
ABSTRACT
Heterotrimeric glutamine amidotransferase CAB (GatCAB) possesses an ammonia-self-sufficient mechanism in which ammonia is produced and used in the inner complex by GatA and GatB, respectively. The X-ray structure of GatCAB revealed that the two identified active sites of GatA and GatB are markedly distant, but are connected in the complex by a channel of 30â
Å in length. In order to clarify whether ammonia is transferred through this channel in GatCAB by visualizing ammonia, neutron diffraction studies are indispensable. Here, GatCAB crystals were grown to approximate dimensions of 2.8 × 0.8 × 0.8â
mm (a volume of 1.8â
mm3) with the aid of a polymer using microseeding and macroseeding processes. Monochromatic neutron diffraction data were collected using the neutron single-crystal diffractometer BIODIFF at the Heinz Maier-Leibnitz Zentrum, Germany. The GatCAB crystals belonged to space group P212121, with unit-cell parameters a = 74.6, b = 94.5, c = 182.5â
Å and with one GatCAB complex (molecular mass 119â
kDa) in the asymmetric unit. This study represented a challenge in current neutron diffraction technology.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Transferases
/
Crystallography, X-Ray
/
Neutron Diffraction
/
Glutamine
Language:
En
Journal:
Acta Crystallogr F Struct Biol Commun
Year:
2019
Document type:
Article
Affiliation country:
Japón