1W20

Structure of Neuraminidase from English duck subtype N6 complexed with 30 mM sialic acid (NANA, Neu5Ac), crystal soaked for 3 hours at 291 K

Entity

Entity ID	Chain ID	Description	Type	Chain length	Formula weight	Number of molecules	DB Name (Accession)	Biological source	Descriptive keywords
1	A, B, C, D (A, B, C, D)	NEURAMINIDASE SUBTYPE N6	polymer	389	43011.5	4	UniProt (Q6XV27) Pfam (PF00064)	INFLUENZA VIRUS TYPE A
2	E, F, H (E, F, H)	2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose	branched		424.4	3	In PDB GlyTouCan (G42666HT)
3	G (G)	alpha-D-mannopyranose-(1-6)-beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose	branched		545.5	1	In PDB GlyTouCan (G41734DZ)
4	BA, CA, I, J, LA... (C, A, D, B)	N-acetyl-alpha-neuraminic acid	non-polymer		309.3	8	Chemie (SIA)
5	DA, K, NA, U (C, A, D, B)	GLYCEROL	non-polymer		92.1	4	Chemie (GOL)
6	EA, L, M, OA, V (C, A, D, B)	2-acetamido-2-deoxy-beta-D-glucopyranose	non-polymer		221.2	5	Chemie (NAG)
7	JA, N, W (C, A, B)	beta-D-mannopyranose	non-polymer		180.2	3	Chemie (BMA)
8	FA, GA, HA, IA, O... (C, A, B)	alpha-D-mannopyranose	non-polymer		180.2	10	Chemie (MAN)
9	AA, KA, PA, R (B, C, D, A)	CALCIUM ION	non-polymer		40.1	4	Chemie (CA)
10	QA, RA, SA, TA (A, B, C, D)	water	water		18.0	1727	Chemie (HOH)

Contents of the asymmetric unit

Polymers	Number of chains	4
	Total formula weight	172046.1
Branched	Number of molecules	4
	Total formula weight	1818.7
Non-Polymers*	Number of molecules	34
	Total formula weight	6450.9
All*	Total formula weight	180315.7

*Water molecules are not included.