Volume 11, Number 10—October 2005
Research
Evolution of H5N1 Avian Influenza Viruses in Asia
Table 1
Amino acid differences among H5 hemagglutinins (HA1)
| Clade 3 | Clade 2 | Clade 1´ | Clade 1 | H3 No. | Functional significance |
|---|---|---|---|---|---|
| N45* | D | D | D | 54† | Antigenic site C |
| S84 | N | N | N | 92 | Antigenic site E |
| A86 | A | A | V | 93 | Antigenic site E |
| N94 | D | D | D (1) | 101 | Near Y91; receptor binding? |
| N124 | D | S | S | 129 | Antigenic site B |
| S129 | S | L | L | 133a | Receptor binding |
| L138 | Q | Q | Q | 142 | Antigenic site A |
| S155 | – | N155 | – | 159 | Antigenic site B |
| T156‡ | A | A | T | 160 | N154 glycosylation motif |
| L175 | L | L | L (2) | 179 | Near H179; receptor binding? |
| T188 | T | T | T (3) | 192 | Near L190; receptor binding? |
| K189 | R | R | K | 193 | Adjacent to receptor binding, antigenic site B |
| E212 | K | K | R | 216 | Antigenic site D |
| S223 | – | N223§ | – (4) | 227 | Receptor binding |
| T263 | A | A | T | 266 | Antigenic site E |
| 325R¶ | Absent | – | – | Absent | HA cleavage efficiency |
*Amino acid residue in single-letter code and position in the mature H5 HA1.
†Equivalent residue number in the mature H3 HA1 aligned with H5 amino acid sequence; –, no change from HK97 clade HA consensus.
‡A156 or S156 were found in certain clade 3 HAs; A156 was present in some HAs from clade 2. HA genes from »50% of isolates collected in 2005 had these substitutions present in only one isolate: 1) to N or V; 2) to M or I; 3) to A, V, or I; or 4) to N.
§Change present exclusively in isolates from humans.
¶Arginine at the start of the polybasic cleavage site, position 325.
1Members of the World Health Organization Global Influenza Program and collaborating laboratories: Jean-Thierry Aubin, Saliha Azebi, Amanda Balish, Jill Banks, Niranjan Bhat, Rick A. Bright, Ian Brown, Philippe Buchy, Ana-Maria Burguiere, Hua-lan Chen, Peter Cheng, Nancy J. Cox, Alice Crosier, Aaron Curns, Frédérique Cuvelier, Guohua Deng, Julia Desheva, Stéphanie Desvaux, Nguyen Hong Diep, Ruben O. Donis, Alan Douglas, Scott F. Dowell, Nguyen Tien Dung, Lindsay Edwards, Keiji Fukuda, Rebecca Garten, Elena Govorkova, Victoria Gregory, Alan Hampson, Nguyen Thi Hong Hanh, Scott Harper, Alan Hay, Erich Hoffmann, Diane Hulse, Masaki Imai, Shigeyuki Itamura, Samadhan Jadhao, Patricia Jeannin, Chun Kang, Jackie Katz, Jae-Hong Kim, Alexander Klimov, Yong-kuk Kwon, Chang-Won Lee, Phuong Song Lien, Yanbing Li, Wilina Lim, Yi Pu Lin, Stephen Lindstom, LaMorris Loftin, Jan Mabry, Le Quynh Mai, Taronna Maines, Jean-Claude Manuguerra, Masaji Mase, Yumi Matsuoka, Margaret McCarron, Marie-Jo Medina, Doan Nguyen, Ai Ninomiya, Masatsugu Obuchi, Takato Odagiri, Malik Peiris, Michael L. Perdue, Jean-Marc Reynes, James Robertson, Claudine Rousseaux, Takehiko Saito, Somchai Sangkitporn, Michael Shaw, James M. Simmerman, M. Slomka, Catherine Smith, San Sorn, Erica Spackman, Klaus Stöhr, David L. Suarez, Haan Woo Sung, David E Swayne, Maryse Tardy-Panit, Masato Tashiro, Pranee Thawatsupha, Terrence Tumpey, Timothy Uyeki, Phan Van Tu, Sylvie van der Werf, Sirenda Vong, Richard Webby, Robert Webster, John Wood, Xiyan Xu, Guan Yi, and Wenqing Zhang. For author affiliations, please Download PDF (37 KB, 2 pages).