Maltose-induced structure of the human cytolsolic sialidase Neu2

Crystal Structure of the Human Cytosolic Sialidase Neu2: EVIDENCE FOR THE DYNAMIC NATURE OF SUBSTRATE RECOGNITION

Neu2, Cytosolic sialidase, N-acetyl-alpha- neuraminidase 2

GSMASLPVLQKESVFQSGAHAYRIPALLYLPGQQSLLAFAEQRASKKDEHAELIVLRRGDYDAPTHQVQWQAQEVVAQAR
LDGHRSMNPCPLYDAQTGTLFLFFIAIPGQVTEQQQLQTRANVTRLCQVTSTDHGRTWSSPRDLTDAAIGPAYREWSTFA
VGPGHCLQLNDRARSLVVPAYAYRKLHPIQRPIPSAFCFLSHDHGRTWARGHFVAQDTLECQVAEVETGEQRVVTLNARS
HLRARVQAQSTNDGLDFQESQLVKKLVEPPPQGCQGSVISFPSPRSGPGSPAQWLLYTHPTHSWQRADLGAYLNPRPPAP
EAWSEPVLLAKGSCAYSDLQSMGTGPDGSPLFGCLYEANDYEEIVFLMFTLKQAFPAEYLPQ

sodium potassium phosphate, sodium chloride, pH 6.2, VAPOR DIFFUSION, HANGING DROP, temperature 289K

the same protein complexed with sialic acid

About CD1/CD2 (LEU A 90), OE1/OE2 (GLU A 218) and
CG1/CG2 (VAL A 325),
there are 3 possible positions for these atoms.
There are two different conformations for each atom.
For convenience, the author assigned as a double
conformation only one of the atoms.(CD2 of LEU 90,
OE1 of GLU 218 and CG1 of VAL 325)
Thus the occupancies of the alternate conformations
are greater than 1.00 and there are chirality errors
at these atoms.
The chirality errors appear at CB (ILE A 105) and CG (BLEU A 365).
About LEU 365, the author could see two conformations, but only the atom CG
was obvious.
The other atoms (respectively CD1 and CD2), if in an other conformation,
would have been
too close than the first conformation.
The author only applied two conformations for the CG atom.
About ILE 105, the author could see density for an other
conformation only for a CG atom, but nothing for the CD1.
The author assigned only 2 conformations for the CG2 atom.
These are the reasons for the chirality errors.

sialidase, neuraminidase, ganglioside, sugar-induced form, hydrolase

MASLPVLQKESVFQSGAHAYRIPALLYLPGQQSLLAFAEQRASKKDEHAELIVLRRGDYDAPTHQVQWQAQEVVAQARLD
GHRSMNPCPLYDAQTGTLFLFFIAIPGQVTEQQQLQTRANVTRLCQVTSTDHGRTWSSPRDLTDAAIGPAYREWSTFAVG
PGHCLQLNDRARSLVVPAYAYRKLHPIQRPIPSAFCFLSHDHGRTWARGHFVAQDTLECQVAEVETGEQRVVTLNARSHL
RARVQAQSTNDGLDFQESQLVKKLVEPPPQGCQGSVISFPSPRSGPGSPAQWLLYTHPTHSWQRADLGAYLNPRPPAPEA
WSEPVLLAKGSCAYSDLQSMGTGPDGSPLFGCLYEANDYEEIVFLMFTLKQAFPAEYLPQ