PDBsum entry 1f8q

Hydrolase

PDB id: 1f8q

Contents

Protein chain

246 a.a. *

Ligands

NAG-NAG-MAN-XYS

PTD ×3

CCN ×2

Waters ×96

* Residue conservation analysis

PDB id:

1f8q

Name:

Hydrolase

Title:

Crystal structure of alpha-momorcharin in acetonitrile-water mixture

Structure:

Alpha-momorcharin. Chain: a. Ec: 3.2.2.22

Source:

Momordica charantia. Balsam pear. Organism_taxid: 3673

Resolution:

2.20Å R-factor: 0.198 R-free: 0.272

Authors:

G.Zhu,Q.Huang,M.Qian,Y.Tang

Key ref:

G.Zhu et al. (2001). Crystal structure of alpha-momorcharin in 80% acetonitrile--water mixture. Biochim Biophys Acta, 1548, 152-158. PubMed id: 11451448 DOI: 10.1016/S0167-4838(01)00235-7

Date:

03-Jul-00 Release date: 26-Jul-00

Protein chain

P16094  (RIP1_MOMCH) -  Ribosome-inactivating protein momordin I from Momordica charantia

Seq: 286 a.a.

Struc: 246 a.a.*

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

Enzyme reactions

• Enzyme class: E.C.3.2.2.22 - rRNA N-glycosylase.
• Reaction: Endohydrolysis of the N-glycosidic bond at one specific adenosine on the 28S rRNA.

DOI no: 10.1016/S0167-4838(01)00235-7

Biochim Biophys Acta 1548:152-158 (2001)

PubMed id: 11451448

Crystal structure of alpha-momorcharin in 80% acetonitrile--water mixture.

G.Zhu, Q.Huang, M.Qian, Y.Tang.

ABSTRACT

Crystals of alpha-momorcharin (MMC) were cross-linked and soaked in an 80% acetonitrile--water mixture and X-ray data were collected to 2.2 A resolution. MMC is a ribosome-inactivating protein with a sugar chain on Asn-227. In previous studies, the whole conformation of the sugar chain could not be obtained in the aqueous system. Here the structure of MMC in a low water system is shown to be similar to the native one, but the sugar chain on Asn-227 is defined by the electron density map. Several oxygen atoms of the oligosaccharide formed intramolecular hydrogen bonds to the protein moiety. The conformation of the residues in the active center is similar to that in the aqueous system. Our results show conformational alteration of the tetrasaccharide of MMC in organic media. They indicate that the oligosaccharides are more rigid in organic solvents. X-ray determination in organic media may be used to solve some structures of oligosaccharides linked to glycoproteins.