3U55

Crystal structure (Type-2) of SAICAR synthetase from Pyrococcus horikoshii OT3

Summary for 3U55

• Entry DOI: 10.2210/pdb3u55/pdb
• Related: 3U54
• Descriptor: Phosphoribosylaminoimidazole-succinocarboxamide synthase, SULFATE ION, ACETATE ION, ... (4 entities in total)
• Functional Keywords: saicar synthetase-like fold, ligase, atp-binding, phosphoribosylaminoimidazole-succinocarboxamide synthetase, purc, de novo purine biosynthesis, ligation of carboxy and amine groups
• Biological source: Pyrococcus horikoshii
• Total number of polymer chains: 1
• Total formula weight: 27731.23

Authors

Manjunath, K.,Kanaujia, S.P.,Kanagaraj, S.,Jeyakanthan, J.,Sekar, K. (deposition date: 2011-10-11, release date: 2012-10-17, Last modification date: 2023-11-01)

Primary citation

Manjunath, K.,Kanaujia, S.P.,Kanagaraj, S.,Jeyakanthan, J.,Sekar, K.
Structure of SAICAR synthetase from Pyrococcus horikoshii OT3: insights into thermal stability
Int.J.Biol.Macromol., 53:7-19, 2013

PubMed Abstract: The first native crystal structure of Phosphoribosylaminoimidazole-succinocarboxamide synthetase (SAICAR synthetase) from a hyperthermophilic organism Pyrococcus horikoshii OT3 was determined in two space groups H3 (Type-1: Resolution 2.35Å) and in C222(1) (Type-2: Resolution 1.9Å). Both are dimeric but Type-1 structure exhibited hexameric arrangement due to the presence of cadmium ions. A comparison has been made on the sequence and structures of all SAICAR synthetases to better understand the differences between mesophilic, thermophilic and hyperthermophilic SAICAR synthetases. These SAICAR synthetases are reasonably similar in sequence and three-dimensional structure; however, differences were visible only in the subtler details of percentage composition of the sequences, salt bridge interactions and non-polar contact areas.

PubMed: 23137517
DOI: 10.1016/j.ijbiomac.2012.10.028

Experimental method

X-RAY DIFFRACTION (1.9 Å)