Finding intermodel H-bonds
Finding intramodel H-bonds
Constraints relaxed by 0.4 angstroms and 20 degrees
Models used:
	#0 2yx0_A.cif

H-bonds (donor, acceptor, hydrogen, D..A dist, D-H..A dist):
GLN 5.A N      GLU 103.A OE1  no hydrogen  2.587  N/A
ASN 7.A N      GLY 27.A O     no hydrogen  3.017  N/A
ASN 9.A N      ARG 28.A O     no hydrogen  2.759  N/A
ASN 9.A ND2    GLN 92.A O     no hydrogen  2.955  N/A
MET 10.A N     PRO 8.A O      no hydrogen  2.704  N/A
ALA 15.A N     PRO 11.A O     no hydrogen  3.147  N/A
GLU 16.A N     LYS 12.A O     no hydrogen  2.915  N/A
LEU 17.A N     GLU 13.A O     no hydrogen  3.044  N/A
PHE 18.A N     VAL 14.A O     no hydrogen  3.098  N/A
ARG 19.A N     ALA 15.A O     no hydrogen  3.123  N/A
ARG 19.A NH1   GLU 16.A OE1   no hydrogen  2.859  N/A
LYS 20.A N     GLU 16.A O     no hydrogen  2.984  N/A
GLN 21.A N     PHE 18.A O     no hydrogen  3.051  N/A
HIS 22.A N     ARG 19.A O     no hydrogen  2.763  N/A
TYR 23.A N     PHE 18.A O     no hydrogen  3.130  N/A
GLU 24.A N     VAL 32.A O     no hydrogen  2.683  N/A
VAL 26.A N     SER 30.A O     no hydrogen  2.875  N/A
GLY 27.A N     GLN 5.A O      no hydrogen  3.095  N/A
ARG 28.A N     ASP 95.A OD2   no hydrogen  2.717  N/A
ARG 28.A NE    ASP 95.A OD1   no hydrogen  3.267  N/A
ARG 28.A NE    ASP 95.A OD2   no hydrogen  3.436  N/A
ARG 28.A NH2   ASP 95.A OD1   no hydrogen  3.379  N/A
HIS 29.A ND1   PRO 66.A O     no hydrogen  2.774  N/A
SER 30.A N     VAL 26.A O     no hydrogen  3.046  N/A
GLY 31.A N     THR 65.A O     no hydrogen  3.105  N/A
VAL 32.A N     GLU 24.A O     no hydrogen  2.906  N/A
LYS 33.A N     GLN 63.A O     no hydrogen  3.286  N/A
TRP 37.A NE1   PHE 47.A O     no hydrogen  2.631  N/A
SER 41.A OG    ARG 46.A O     no hydrogen  3.484  N/A
LEU 42.A N     LEU 38.A O     no hydrogen  3.089  N/A
LEU 42.A N     LYS 39.A O     no hydrogen  2.817  N/A
THR 43.A N     LYS 39.A O     no hydrogen  3.010  N/A
GLU 44.A N     LYS 40.A O     no hydrogen  2.643  N/A
ARG 46.A N     LYS 40.A O     no hydrogen  3.372  N/A
CYS 48.A SG    SER 58.A OG    no hydrogen  3.043  N/A
TYR 49.A OH    GLU 258.A OE1  no hydrogen  3.133  N/A
GLN 51.A N     CYS 48.A O     no hydrogen  3.092  N/A
LYS 52.A N     CYS 48.A O     no hydrogen  3.501  N/A
LYS 52.A NZ    GLU 296.A O    no hydrogen  3.077  N/A
PHE 53.A N     TYR 49.A O     no hydrogen  2.742  N/A
TYR 54.A N     LYS 50.A O     no hydrogen  2.945  N/A
TYR 54.A OH    GLU 258.A OE2  no hydrogen  2.494  N/A
GLY 55.A N     GLN 51.A O     no hydrogen  2.796  N/A
ILE 56.A N     LYS 50.A O     no hydrogen  3.302  N/A
HIS 59.A NE2   GLU 126.A OE2  no hydrogen  2.698  N/A
ARG 60.A N     HIS 57.A O     no hydrogen  2.748  N/A
ARG 60.A NE    GLU 126.A O    no hydrogen  3.057  N/A
ARG 60.A NH2   ASN 129.A O    no hydrogen  2.979  N/A
CYS 61.A N     SER 58.A O     no hydrogen  3.070  N/A
LEU 62.A N     HIS 132.A O    no hydrogen  2.672  N/A
GLN 63.A NE2   LYS 33.A O     no hydrogen  3.407  N/A
MET 64.A N     ALA 134.A O    no hydrogen  2.909  N/A
THR 65.A N     GLY 31.A O     no hydrogen  3.142  N/A
THR 65.A OG1   SER 138.A O    no hydrogen  3.051  N/A
VAL 67.A N     THR 65.A OG1   no hydrogen  3.045  N/A
LEU 68.A N     HIS 29.A O     no hydrogen  2.910  N/A
CYS 71.A N     GLY 87.A O     no hydrogen  3.111  N/A
CYS 71.A SG    HIS 73.A O     no hydrogen  3.618  N/A
THR 72.A OG1   THR 168.A OG1  no hydrogen  2.645  N/A
HIS 73.A NE2   TYR 198.A OH   no hydrogen  2.888  N/A
ASN 74.A N     ILE 203.A O    no hydrogen  2.982  N/A
ILE 76.A N     VAL 201.A O    no hydrogen  3.035  N/A
CYS 78.A N     CYS 75.A O     no hydrogen  3.083  N/A
ARG 80.A NE    GLU 83.A O     no hydrogen  2.997  N/A
ARG 80.A NH1   CYS 75.A O     no hydrogen  3.034  N/A
ARG 80.A NH2   GLU 83.A O     no hydrogen  3.284  N/A
LEU 86.A N     ALA 69.A O     no hydrogen  2.997  N/A
TRP 94.A NE1   LEU 90.A O     no hydrogen  2.739  N/A
ASP 95.A N     HIS 29.A NE2   no hydrogen  2.906  N/A
ALA 98.A N     ASP 96.A OD1   no hydrogen  2.662  N/A
PHE 99.A N     ASP 96.A OD1   no hydrogen  3.464  N/A
ILE 100.A N    ASP 96.A O     no hydrogen  3.128  N/A
VAL 101.A N    PRO 97.A O     no hydrogen  3.020  N/A
GLU 102.A N    ALA 98.A O     no hydrogen  2.973  N/A
GLU 103.A N    PHE 99.A O     no hydrogen  2.916  N/A
SER 104.A N    ILE 100.A O    no hydrogen  2.859  N/A
SER 104.A OG   ILE 100.A O    no hydrogen  2.744  N/A
ILE 105.A N    VAL 101.A O    no hydrogen  3.017  N/A
LYS 106.A N    GLU 102.A O    no hydrogen  3.132  N/A
LYS 106.A NZ   GLU 103.A OE2  no hydrogen  2.968  N/A
ALA 107.A N    GLU 103.A O    no hydrogen  2.677  N/A
GLN 108.A N    SER 104.A O    no hydrogen  2.766  N/A
ARG 109.A N    ILE 105.A O    no hydrogen  3.158  N/A
ARG 109.A NE   TRP 128.A O    no hydrogen  2.925  N/A
ARG 109.A NH2  TRP 128.A O    no hydrogen  3.026  N/A
LYS 110.A N    LYS 106.A O    no hydrogen  2.940  N/A
LYS 110.A NZ   GLU 24.A OE1   no hydrogen  3.365  N/A
LYS 110.A NZ   GLU 24.A OE2   no hydrogen  2.920  N/A
LEU 111.A N    ALA 107.A O    no hydrogen  3.023  N/A
LEU 112.A N    GLN 108.A O    no hydrogen  2.905  N/A
ILE 113.A N    ARG 109.A O    no hydrogen  2.839  N/A
GLY 114.A N    LEU 111.A O    no hydrogen  3.071  N/A
LYS 116.A NZ   TYR 115.A O    no hydrogen  2.366  N/A
ASP 120.A N    LEU 42.A O     no hydrogen  2.907  N/A
LYS 122.A NZ   GLU 126.A OE2  no hydrogen  3.083  N/A
LYS 123.A N    ASP 120.A OD1  no hydrogen  2.903  N/A
GLU 125.A N    LYS 121.A O    no hydrogen  3.278  N/A
GLU 126.A N    LYS 122.A O    no hydrogen  3.337  N/A
ALA 127.A N    LYS 123.A O    no hydrogen  2.975  N/A
TRP 128.A N    PHE 124.A O    no hydrogen  2.959  N/A
TRP 128.A N    GLU 125.A O    no hydrogen  3.217  N/A
ASN 129.A N    GLU 126.A O    no hydrogen  3.122  N/A
ASN 129.A ND2  GLU 125.A O    no hydrogen  2.428  N/A
THR 131.A N    ARG 60.A O     no hydrogen  2.919  N/A
HIS 132.A N    ARG 60.A O     no hydrogen  3.083  N/A
HIS 132.A ND1  THR 160.A OG1  no hydrogen  2.749  N/A
ALA 133.A N    THR 160.A O    no hydrogen  2.857  N/A
ALA 134.A N    LEU 62.A O     no hydrogen  2.802  N/A
ILE 135.A N    PHE 162.A O    no hydrogen  2.817  N/A
SER 136.A N    MET 64.A O     no hydrogen  3.079  N/A
LEU 137.A N    MET 64.A O     no hydrogen  3.181  N/A
SER 138.A OG   LEU 68.A O     no hydrogen  2.925  N/A
GLU 140.A N    TRP 70.A O     no hydrogen  2.995  N/A
MET 142.A N    GLU 140.A OE1  no hydrogen  3.009  N/A
LEU 143.A N    GLU 140.A O    no hydrogen  3.021  N/A
TYR 144.A N    PRO 141.A O    no hydrogen  2.957  N/A
TYR 144.A OH   ASP 95.A O     no hydrogen  2.665  N/A
LEU 150.A N    TYR 146.A O    no hydrogen  2.815  N/A
VAL 151.A N    MET 147.A O    no hydrogen  2.782  N/A
GLU 152.A N    GLY 148.A O    no hydrogen  3.080  N/A
GLU 153.A N    ASP 149.A O    no hydrogen  2.857  N/A
PHE 154.A N    LEU 150.A O    no hydrogen  3.121  N/A
HIS 155.A N    VAL 151.A O    no hydrogen  3.017  N/A
HIS 155.A NE2  THR 161.A OG1  no hydrogen  2.770  N/A
LYS 156.A N    GLU 152.A O    no hydrogen  2.697  N/A
LYS 156.A NZ   GLU 153.A OE2  no hydrogen  2.736  N/A
ARG 157.A N    GLU 153.A O    no hydrogen  3.338  N/A
ARG 157.A N    PHE 154.A O    no hydrogen  3.034  N/A
ARG 157.A NE   GLU 102.A OE1  no hydrogen  2.636  N/A
ARG 157.A NH1  GLU 153.A O    no hydrogen  3.072  N/A
ARG 157.A NH1  GLU 153.A OE1  no hydrogen  2.439  N/A
GLY 158.A N    HIS 155.A O    no hydrogen  2.897  N/A
PHE 159.A N    PHE 154.A O    no hydrogen  2.955  N/A
THR 160.A N    THR 131.A O    no hydrogen  2.748  N/A
THR 160.A OG1  THR 131.A O    no hydrogen  3.298  N/A
THR 161.A N    THR 184.A OG1  no hydrogen  2.705  N/A
THR 161.A OG1  HIS 155.A NE2  no hydrogen  2.770  N/A
PHE 162.A N    ALA 133.A O    no hydrogen  3.026  N/A
ILE 163.A N    GLN 185.A O    no hydrogen  3.078  N/A
VAL 164.A N    ILE 135.A O    no hydrogen  3.055  N/A
THR 165.A N    TYR 187.A O    no hydrogen  2.917  N/A
THR 165.A OG1  GLU 140.A OE1  no hydrogen  2.610  N/A
THR 165.A OG1  GLU 140.A OE2  no hydrogen  3.384  N/A
ASN 166.A N    GLU 140.A OE2  no hydrogen  2.937  N/A
ASN 166.A ND2  THR 72.A OG1   no hydrogen  3.140  N/A
GLY 167.A N    THR 165.A OG1  no hydrogen  3.014  N/A
THR 168.A N    ASN 166.A OD1  no hydrogen  2.976  N/A
THR 168.A OG1  THR 72.A OG1   no hydrogen  2.645  N/A
THR 168.A OG1  ASN 166.A OD1  no hydrogen  2.838  N/A
ARG 172.A N    ILE 169.A O    no hydrogen  3.076  N/A
ARG 172.A NE   MET 142.A O    no hydrogen  2.964  N/A
ARG 172.A NE   TYR 144.A O    no hydrogen  2.802  N/A
ARG 172.A NH1  GLU 175.A OE1  no hydrogen  3.107  N/A
ARG 172.A NH2  MET 142.A O    no hydrogen  3.140  N/A
GLU 174.A N    PRO 170.A O    no hydrogen  2.920  N/A
GLU 175.A N    GLU 171.A O    no hydrogen  3.062  N/A
MET 176.A N    ARG 172.A O    no hydrogen  2.962  N/A
ILE 177.A N    LEU 173.A O    no hydrogen  2.812  N/A
LYS 178.A N    GLU 174.A O    no hydrogen  2.867  N/A
GLU 179.A N    GLU 175.A O    no hydrogen  2.947  N/A
ASP 180.A N    ILE 177.A O    no hydrogen  2.888  N/A
LYS 181.A N    MET 176.A O    no hydrogen  2.742  N/A
LYS 181.A NZ   ASP 149.A OD1  no hydrogen  2.674  N/A
LYS 181.A NZ   GLU 179.A OE1  no hydrogen  2.873  N/A
THR 184.A N    THR 161.A OG1  no hydrogen  2.964  N/A
GLN 185.A N    THR 161.A O    no hydrogen  2.935  N/A
LEU 186.A N    ARG 226.A O    no hydrogen  2.832  N/A
TYR 187.A N    ILE 163.A O    no hydrogen  2.768  N/A
VAL 188.A N    VAL 228.A O    no hydrogen  3.053  N/A
SER 189.A N    THR 165.A O    no hydrogen  2.789  N/A
ILE 190.A N    ARG 230.A O    no hydrogen  2.877  N/A
THR 197.A N    ASP 194.A OD1  no hydrogen  2.707  N/A
THR 197.A OG1  ASP 194.A OD1  no hydrogen  2.534  N/A
THR 197.A OG1  ASP 194.A OD2  no hydrogen  3.314  N/A
THR 197.A OG1  HIS 240.A NE2  no hydrogen  3.181  N/A
TYR 198.A N    ASP 194.A O    no hydrogen  2.852  N/A
TYR 198.A OH   HIS 73.A NE2   no hydrogen  2.888  N/A
ASN 199.A N    ILE 195.A O    no hydrogen  3.135  N/A
SER 200.A N    GLU 196.A O    no hydrogen  3.028  N/A
SER 200.A OG   GLU 196.A O    no hydrogen  3.202  N/A
SER 200.A OG   THR 197.A O    no hydrogen  3.301  N/A
VAL 201.A N    THR 197.A O    no hydrogen  2.818  N/A
ASN 202.A N    TYR 198.A O    no hydrogen  2.954  N/A
ASN 202.A ND2  THR 191.A OG1  no hydrogen  2.702  N/A
ILE 203.A N    ASN 199.A O    no hydrogen  3.105  N/A
MET 205.A N    THR 72.A O     no hydrogen  2.816  N/A
ARG 212.A N    ASP 208.A O    no hydrogen  3.106  N/A
ARG 212.A NE   THR 168.A O    no hydrogen  2.564  N/A
ARG 212.A NH1  ASP 208.A OD2  no hydrogen  2.987  N/A
ARG 212.A NH2  GLU 171.A OE1  no hydrogen  2.729  N/A
ILE 213.A N    GLY 209.A O    no hydrogen  2.863  N/A
LEU 214.A N    TRP 210.A O    no hydrogen  2.988  N/A
ARG 215.A N    GLU 211.A O    no hydrogen  2.959  N/A
PHE 216.A N    ARG 212.A O    no hydrogen  2.765  N/A
LEU 217.A N    ILE 213.A O    no hydrogen  2.910  N/A
GLU 218.A N    LEU 214.A O    no hydrogen  3.160  N/A
LEU 219.A N    ARG 215.A O    no hydrogen  2.884  N/A
MET 220.A N    PHE 216.A O    no hydrogen  3.028  N/A
MET 220.A N    LEU 217.A O    no hydrogen  3.017  N/A
ARG 221.A N    GLU 218.A O    no hydrogen  3.416  N/A
LEU 223.A N    MET 220.A O    no hydrogen  2.935  N/A
THR 225.A N    LEU 223.A O    no hydrogen  2.774  N/A
THR 225.A OG1  PRO 183.A O    no hydrogen  2.555  N/A
THR 225.A OG1  THR 184.A O    no hydrogen  2.919  N/A
ARG 226.A N    THR 184.A O    no hydrogen  3.317  N/A
ARG 226.A NE   GLN 185.A OE1  no hydrogen  2.869  N/A
ARG 226.A NH1  GLY 316.A O    no hydrogen  2.997  N/A
ARG 226.A NH1  GLY 319.A O    no hydrogen  2.816  N/A
ARG 226.A NH2  GLN 185.A OE1  no hydrogen  3.074  N/A
ARG 226.A NH2  ARG 320.A O    no hydrogen  2.876  N/A
VAL 228.A N    LEU 186.A O    no hydrogen  2.927  N/A
VAL 229.A N    PHE 256.A O    no hydrogen  2.961  N/A
ARG 230.A N    VAL 188.A O    no hydrogen  2.974  N/A
ARG 230.A NE   GLU 258.A OE1  no hydrogen  3.001  N/A
ARG 230.A NH2  GLU 258.A OE1  no hydrogen  3.538  N/A
LEU 231.A N    GLU 258.A O    no hydrogen  2.792  N/A
LEU 233.A N    LYS 260.A O    no hydrogen  2.701  N/A
VAL 234.A N    ASN 238.A OD1  no hydrogen  2.703  N/A
LYS 235.A N    ASN 270.A O    no hydrogen  2.627  N/A
GLU 237.A N    VAL 234.A O    no hydrogen  3.024  N/A
ASN 238.A N    VAL 234.A O    no hydrogen  3.126  N/A
ASN 238.A ND2  THR 191.A O    no hydrogen  2.927  N/A
ASN 238.A ND2  THR 232.A O    no hydrogen  2.937  N/A
HIS 240.A ND1  SER 241.A OG   no hydrogen  3.084  N/A
SER 241.A OG   HIS 240.A ND1  no hydrogen  3.084  N/A
GLU 243.A N    GLU 243.A OE1  no hydrogen  2.556  N/A
LYS 244.A N    SER 241.A O    no hydrogen  2.710  N/A
TYR 245.A N    SER 241.A O    no hydrogen  3.162  N/A
TYR 245.A OH   ASN 238.A O    no hydrogen  2.764  N/A
ALA 246.A N    PRO 242.A O    no hydrogen  2.967  N/A
LYS 247.A N    GLU 243.A O    no hydrogen  3.347  N/A
LEU 248.A N    LYS 244.A O    no hydrogen  3.299  N/A
ILE 249.A N    TYR 245.A O    no hydrogen  2.857  N/A
LEU 250.A N    ALA 246.A O    no hydrogen  2.716  N/A
LYS 251.A N    LYS 247.A O    no hydrogen  3.178  N/A
LYS 251.A N    LEU 248.A O    no hydrogen  3.099  N/A
LYS 251.A NZ   GLU 218.A OE2  no hydrogen  2.647  N/A
ALA 252.A N    ILE 249.A O    no hydrogen  2.877  N/A
ARG 253.A N    ILE 249.A O    no hydrogen  2.860  N/A
MET 255.A N    THR 227.A OG1  no hydrogen  2.945  N/A
PHE 256.A N    THR 227.A O    no hydrogen  3.048  N/A
VAL 257.A N    ILE 305.A O    no hydrogen  2.829  N/A
GLU 258.A N    VAL 229.A O    no hydrogen  3.007  N/A
ALA 259.A N    VAL 303.A O    no hydrogen  2.946  N/A
LYS 260.A N    LEU 231.A O    no hydrogen  2.779  N/A
ALA 261.A N    ARG 301.A O    no hydrogen  3.091  N/A
TYR 262.A N    LEU 233.A O    no hydrogen  2.997  N/A
LEU 266.A N    ASN 264.A O    no hydrogen  2.461  N/A
THR 267.A N    ASN 270.A OD1  no hydrogen  2.579  N/A
ASN 269.A N    THR 267.A OG1  no hydrogen  2.636  N/A
ASN 270.A ND2  LYS 235.A O    no hydrogen  3.110  N/A
SER 273.A N    ASP 276.A OD2  no hydrogen  2.630  N/A
HIS 274.A NE2  GLU 296.A OE1  no hydrogen  2.749  N/A
ASP 276.A N    SER 273.A OG   no hydrogen  2.788  N/A
ILE 277.A N    SER 273.A O    no hydrogen  3.052  N/A
ARG 278.A N    HIS 274.A O    no hydrogen  2.895  N/A
GLU 279.A N    GLN 275.A O    no hydrogen  3.037  N/A
PHE 280.A N    ASP 276.A O    no hydrogen  2.914  N/A
ALA 281.A N    ILE 277.A O    no hydrogen  2.769  N/A
GLU 282.A N    ARG 278.A O    no hydrogen  2.896  N/A
ALA 283.A N    GLU 279.A O    no hydrogen  2.883  N/A
LEU 284.A N    PHE 280.A O    no hydrogen  2.808  N/A
VAL 285.A N    ALA 281.A O    no hydrogen  2.819  N/A
LYS 286.A N    GLU 282.A O    no hydrogen  3.306  N/A
LYS 286.A NZ   GLU 282.A O    no hydrogen  3.108  N/A
HIS 287.A N    LEU 284.A O    no hydrogen  2.799  N/A
LEU 288.A N    VAL 285.A O    no hydrogen  2.955  N/A
TYR 291.A N    LEU 288.A O    no hydrogen  3.193  N/A
TYR 291.A OH   PRO 254.A O    no hydrogen  2.627  N/A
HIS 292.A N    MET 306.A O    no hydrogen  2.998  N/A
HIS 292.A ND1  ASP 308.A OD1  no hydrogen  2.498  N/A
HIS 292.A NE2  GLU 294.A OE1  no hydrogen  3.148  N/A
GLU 294.A N    LEU 304.A O    no hydrogen  2.783  N/A
ASP 295.A N    LEU 304.A O    no hydrogen  3.308  N/A
GLU 296.A N    ASP 295.A OD1  no hydrogen  2.757  N/A
TYR 297.A N    VAL 302.A O    no hydrogen  2.887  N/A
SER 300.A N    TYR 297.A O    no hydrogen  2.941  N/A
ARG 301.A N    GLU 298.A O    no hydrogen  2.763  N/A
ARG 301.A NH1  PRO 272.A O    no hydrogen  2.650  N/A
VAL 302.A N    TYR 297.A O    no hydrogen  3.357  N/A
VAL 303.A N    ALA 259.A O    no hydrogen  2.930  N/A
LEU 304.A N    ASP 295.A O    no hydrogen  2.836  N/A
ILE 305.A N    VAL 257.A O    no hydrogen  2.753  N/A
MET 306.A N    HIS 292.A O    no hydrogen  2.881  N/A
ARG 307.A N    MET 255.A O    no hydrogen  2.915  N/A
ARG 307.A NE   ASP 309.A OD1  no hydrogen  2.657  N/A
ARG 307.A NH1  ARG 253.A O    no hydrogen  2.731  N/A
ASP 308.A N    GLY 290.A O    no hydrogen  2.874  N/A
VAL 310.A N    ARG 307.A O    no hydrogen  2.819  N/A
ASP 311.A N    GLU 318.A O    no hydrogen  2.982  N/A
GLN 313.A N    ASP 311.A OD1  no hydrogen  2.907  N/A
GLY 314.A N    ASP 311.A O    no hydrogen  2.974  N/A
GLY 316.A N    PHE 321.A O    no hydrogen  2.794  N/A
GLY 319.A N    GLY 316.A O    no hydrogen  3.185  N/A
ARG 320.A N    ASP 311.A O    no hydrogen  2.939  N/A
ARG 320.A NE   PHE 53.A O     no hydrogen  2.898  N/A
ARG 320.A NH1  GLU 294.A OE2  no hydrogen  2.900  N/A
ARG 320.A NH2  LYS 52.A O     no hydrogen  2.847  N/A
ARG 320.A NH2  ASP 295.A OD2  no hydrogen  2.364  N/A
PHE 321.A N    GLY 314.A O    no hydrogen  3.103  N/A
ILE 322.A N    TYR 54.A O     no hydrogen  2.921  N/A