Finding intermodel H-bonds Finding intramodel H-bonds Constraints relaxed by 0.4 angstroms and 20 degrees Models used: #0 1bh2_A.cif H-bonds (donor, acceptor, hydrogen, D..A dist, D-H..A dist): ARG 1.A N ASP 162.A O no hydrogen 3.519 N/A VAL 3.A N HIS 164.A O no hydrogen 2.988 N/A LYS 4.A N THR 188.A OG1 no hydrogen 2.970 N/A LYS 4.A NZ CYS 183.A O no hydrogen 2.952 N/A LYS 4.A NZ GLU 185.A O no hydrogen 2.693 N/A LEU 5.A N LYS 166.A O no hydrogen 3.071 N/A LEU 6.A N ALA 189.A O no hydrogen 3.002 N/A LEU 7.A N PHE 168.A O no hydrogen 2.712 N/A LEU 8.A N ILE 191.A O no hydrogen 2.923 N/A SER 13.A OG ALA 10.A O no hydrogen 2.831 N/A LYS 15.A NZ GLY 9.A O no hydrogen 3.016 N/A LYS 15.A NZ SER 13.A OG no hydrogen 3.323 N/A SER 16.A OG THR 150.A OG1 no hydrogen 2.938 N/A SER 16.A OG ASP 169.A OD2 no hydrogen 2.667 N/A ILE 18.A N GLY 14.A O no hydrogen 3.168 N/A VAL 19.A N LYS 15.A O no hydrogen 3.208 N/A LYS 20.A N SER 16.A O no hydrogen 3.067 N/A GLN 21.A N THR 17.A O no hydrogen 3.011 N/A GLN 21.A NE2 SER 295.A O no hydrogen 2.585 N/A MET 22.A N ILE 18.A O no hydrogen 3.105 N/A LYS 23.A N LYS 20.A O no hydrogen 3.137 N/A LYS 23.A NZ GLY 29.A O no hydrogen 3.498 N/A LYS 23.A NZ GLU 34.A OE1 no hydrogen 3.302 N/A LYS 23.A NZ GLU 34.A OE2 no hydrogen 3.332 N/A ILE 24.A N LYS 20.A O no hydrogen 3.245 N/A ILE 25.A N GLN 21.A O no hydrogen 2.769 N/A HIS 26.A N MET 22.A O no hydrogen 2.725 N/A GLU 27.A N LYS 23.A O no hydrogen 3.004 N/A GLY 29.A N LYS 23.A O no hydrogen 3.183 N/A TYR 30.A N GLN 140.A OE1 no hydrogen 2.910 N/A SER 31.A N GLU 34.A OE1 no hydrogen 2.765 N/A SER 31.A OG GLU 34.A OE1 no hydrogen 2.975 N/A GLU 33.A N GLU 33.A OE1 no hydrogen 2.760 N/A GLU 34.A N SER 31.A OG no hydrogen 3.156 N/A CYS 35.A N SER 31.A O no hydrogen 2.714 N/A CYS 35.A SG TYR 30.A O no hydrogen 3.639 N/A CYS 35.A SG SER 31.A O no hydrogen 3.408 N/A CYS 35.A SG PRO 138.A O no hydrogen 3.250 N/A LYS 36.A N GLU 32.A O no hydrogen 2.842 N/A GLN 37.A N GLU 33.A O no hydrogen 3.262 N/A GLN 37.A N GLU 34.A O no hydrogen 3.105 N/A TYR 38.A N CYS 35.A O no hydrogen 2.926 N/A LYS 39.A N LYS 36.A O no hydrogen 3.092 N/A LYS 39.A NZ TYR 136.A O no hydrogen 3.238 N/A VAL 42.A N TYR 38.A O no hydrogen 2.864 N/A TYR 43.A N LYS 39.A O no hydrogen 2.993 N/A TYR 43.A OH ILE 131.A O no hydrogen 2.754 N/A SER 44.A N ALA 40.A O no hydrogen 2.860 N/A ASN 45.A N VAL 41.A O no hydrogen 2.794 N/A ASN 45.A ND2 ARG 147.A O no hydrogen 3.156 N/A THR 46.A N VAL 42.A O no hydrogen 3.024 N/A THR 46.A OG1 VAL 42.A O no hydrogen 2.852 N/A ILE 47.A N TYR 43.A O no hydrogen 3.057 N/A GLN 48.A N SER 44.A O no hydrogen 3.043 N/A SER 49.A N ASN 45.A O no hydrogen 3.060 N/A SER 49.A OG ASN 45.A O no hydrogen 2.637 N/A ILE 50.A N THR 46.A O no hydrogen 3.188 N/A ILE 51.A N ILE 47.A O no hydrogen 3.036 N/A ALA 52.A N GLN 48.A O no hydrogen 2.828 N/A ILE 53.A N SER 49.A O no hydrogen 2.978 N/A ILE 54.A N ILE 50.A O no hydrogen 2.907 N/A ARG 55.A N ILE 51.A O no hydrogen 2.723 N/A ALA 56.A N ALA 52.A O no hydrogen 2.994 N/A MET 57.A N ILE 53.A O no hydrogen 3.146 N/A GLY 58.A N ARG 55.A O no hydrogen 3.157 N/A ARG 59.A N ARG 55.A O no hydrogen 3.230 N/A LEU 60.A N ALA 56.A O no hydrogen 2.746 N/A ILE 62.A N MET 57.A O no hydrogen 2.782 N/A GLY 65.A N ASP 102.A OD2 no hydrogen 2.682 N/A ASP 66.A N ASP 102.A OD1 no hydrogen 2.949 N/A ARG 69.A N ASP 66.A O no hydrogen 3.243 N/A ARG 69.A NE ASP 72.A OD2 no hydrogen 2.779 N/A ARG 69.A NH2 ASP 72.A OD2 no hydrogen 3.024 N/A ALA 70.A N ALA 67.A O no hydrogen 3.038 N/A ASP 71.A N ALA 68.A O no hydrogen 3.085 N/A ALA 73.A N ARG 69.A O no hydrogen 2.704 N/A ARG 74.A N ALA 70.A O no hydrogen 3.208 N/A ARG 74.A NH1 ASP 71.A OD1 no hydrogen 2.954 N/A ARG 74.A NH2 ASP 71.A OD1 no hydrogen 2.965 N/A GLN 75.A N ASP 71.A O no hydrogen 2.959 N/A LEU 76.A N ASP 72.A O no hydrogen 2.811 N/A VAL 78.A N ARG 74.A O no hydrogen 3.473 N/A LEU 79.A N GLN 75.A O no hydrogen 3.052 N/A ALA 80.A N LEU 76.A O no hydrogen 2.782 N/A ALA 82.A N LEU 79.A O no hydrogen 3.272 N/A GLU 85.A N ALA 82.A O no hydrogen 2.827 N/A GLY 86.A N ALA 83.A O no hydrogen 3.167 N/A PHE 87.A N ALA 82.A O no hydrogen 3.229 N/A LEU 92.A N THR 89.A OG1 no hydrogen 3.259 N/A ALA 93.A N THR 89.A O no hydrogen 2.833 N/A GLY 94.A N ALA 90.A O no hydrogen 2.817 N/A VAL 95.A N GLU 91.A O no hydrogen 3.080 N/A ILE 96.A N LEU 92.A O no hydrogen 2.984 N/A LYS 97.A N ALA 93.A O no hydrogen 2.895 N/A LYS 97.A NZ ASP 129.A OD2 no hydrogen 3.184 N/A ARG 98.A N GLY 94.A O no hydrogen 3.056 N/A ARG 98.A NE ASP 72.A OD1 no hydrogen 3.468 N/A ARG 98.A NE ASP 72.A OD2 no hydrogen 3.065 N/A ARG 98.A NH2 ASP 72.A OD1 no hydrogen 3.155 N/A LEU 99.A N VAL 95.A O no hydrogen 3.134 N/A TRP 100.A N ILE 96.A O no hydrogen 2.870 N/A TRP 100.A NE1 ASN 126.A OD1 no hydrogen 2.909 N/A LYS 101.A N LYS 97.A O no hydrogen 3.113 N/A ASP 102.A N LEU 99.A O no hydrogen 3.125 N/A GLY 104.A N ASP 102.A OD2 no hydrogen 3.270 N/A VAL 105.A N ASP 102.A OD2 no hydrogen 3.334 N/A GLN 106.A N ASP 102.A O no hydrogen 2.946 N/A GLN 106.A NE2 TRP 100.A O no hydrogen 2.585 N/A ALA 107.A N SER 103.A O no hydrogen 2.815 N/A CYS 108.A N GLY 104.A O no hydrogen 2.940 N/A CYS 108.A SG ILE 53.A O no hydrogen 3.435 N/A CYS 108.A SG TYR 115.A OH no hydrogen 3.816 N/A PHE 109.A N VAL 105.A O no hydrogen 2.804 N/A ASN 110.A N GLN 106.A O no hydrogen 2.908 N/A ARG 111.A N CYS 108.A O no hydrogen 2.969 N/A ARG 111.A NE GLU 114.A OE2 no hydrogen 2.762 N/A ARG 111.A NH2 GLU 114.A OE1 no hydrogen 2.710 N/A ARG 111.A NH2 GLU 114.A OE2 no hydrogen 3.378 N/A SER 112.A N PHE 109.A O no hydrogen 3.271 N/A ARG 113.A NE ASP 200.A O no hydrogen 2.839 N/A ARG 113.A NH2 ASP 200.A O no hydrogen 3.567 N/A GLU 114.A N ARG 111.A O no hydrogen 2.859 N/A TYR 115.A N SER 112.A O no hydrogen 2.974 N/A TYR 115.A OH CYS 108.A O no hydrogen 2.846 N/A GLN 116.A NE2 VAL 202.A O no hydrogen 3.591 N/A ASN 118.A ND2 GLN 48.A OE1 no hydrogen 3.690 N/A SER 120.A OG ARG 145.A O no hydrogen 2.750 N/A ALA 121.A N ASN 118.A O no hydrogen 3.137 N/A TYR 123.A OH ASP 142.A OD1 no hydrogen 2.630 N/A TYR 124.A N SER 120.A O no hydrogen 3.059 N/A TYR 124.A OH ASP 142.A O no hydrogen 2.704 N/A LEU 125.A N ALA 121.A O no hydrogen 2.737 N/A ASN 126.A N ALA 122.A O no hydrogen 2.669 N/A ASP 127.A N TYR 124.A O no hydrogen 3.212 N/A ARG 130.A N ASP 127.A O no hydrogen 3.138 N/A ARG 130.A NH1 ASP 142.A OD2 no hydrogen 2.817 N/A ARG 130.A NH2 ASP 127.A OD2 no hydrogen 3.100 N/A ARG 130.A NH2 ASP 142.A OD1 no hydrogen 2.815 N/A ARG 130.A NH2 ASP 142.A OD2 no hydrogen 3.409 N/A ILE 131.A N ASP 127.A O no hydrogen 3.183 N/A ALA 132.A N LEU 128.A O no hydrogen 3.138 N/A GLN 133.A N ARG 130.A O no hydrogen 3.324 N/A TYR 136.A OH ASP 142.A OD2 no hydrogen 2.734 N/A THR 139.A N ASP 142.A OD2 no hydrogen 3.142 N/A GLN 140.A NE2 TYR 30.A O no hydrogen 3.083 N/A GLN 141.A NE2 THR 296.A O no hydrogen 2.985 N/A ASP 142.A N THR 139.A OG1 no hydrogen 3.300 N/A VAL 143.A N THR 139.A O no hydrogen 3.132 N/A LEU 144.A N GLN 140.A O no hydrogen 2.974 N/A ARG 145.A N GLN 141.A O no hydrogen 2.879 N/A ARG 145.A NE GLN 141.A OE1 no hydrogen 2.657 N/A ARG 145.A NH2 GLN 141.A OE1 no hydrogen 3.252 N/A THR 146.A N VAL 143.A O no hydrogen 3.014 N/A THR 146.A OG1 VAL 143.A O no hydrogen 2.654 N/A ARG 147.A N ASN 45.A OD1 no hydrogen 2.826 N/A THR 150.A OG1 SER 16.A OG no hydrogen 2.938 N/A GLY 152.A N GLU 176.A OE1 no hydrogen 3.252 N/A VAL 154.A N ASP 169.A O no hydrogen 2.884 N/A THR 156.A N MET 167.A O no hydrogen 2.975 N/A HIS 157.A NE2 GLU 155.A OE2 no hydrogen 2.605 N/A PHE 158.A N PHE 165.A O no hydrogen 3.126 N/A PHE 160.A N LEU 163.A O no hydrogen 2.789 N/A LYS 161.A NZ ASP 306.A OD1 no hydrogen 2.637 N/A LYS 161.A NZ ASP 310.A OD1 no hydrogen 2.784 N/A LEU 163.A N PHE 160.A O no hydrogen 2.984 N/A HIS 164.A N ARG 1.A O no hydrogen 2.630 N/A PHE 165.A N PHE 158.A O no hydrogen 2.688 N/A LYS 166.A N VAL 3.A O no hydrogen 2.817 N/A MET 167.A N THR 156.A O no hydrogen 2.867 N/A PHE 168.A N LEU 5.A O no hydrogen 2.735 N/A ASP 169.A N VAL 154.A O no hydrogen 2.953 N/A ARG 174.A N GLU 205.A OE2 no hydrogen 2.999 N/A ARG 174.A NH1 ASP 206.A OD2 no hydrogen 3.566 N/A GLU 176.A N GLN 173.A O no hydrogen 2.842 N/A ARG 177.A N GLN 173.A O no hydrogen 3.125 N/A ARG 177.A N ARG 174.A O no hydrogen 3.262 N/A ARG 177.A NE GLY 172.A O no hydrogen 2.542 N/A ARG 177.A NH1 GLU 214.A OE2 no hydrogen 3.093 N/A ARG 177.A NH2 GLY 172.A O no hydrogen 3.207 N/A ARG 177.A NH2 GLU 214.A OE2 no hydrogen 2.854 N/A LYS 178.A NZ SER 175.A O no hydrogen 2.577 N/A LYS 179.A N GLU 176.A O no hydrogen 2.795 N/A LYS 179.A NZ GLU 176.A OE1 no hydrogen 3.357 N/A TRP 180.A N ARG 177.A O no hydrogen 3.423 N/A TRP 180.A NE1 GLY 171.A O no hydrogen 2.712 N/A HIS 182.A N LYS 179.A O no hydrogen 3.143 N/A CYS 183.A N TRP 180.A O no hydrogen 2.948 N/A PHE 184.A N ILE 181.A O no hydrogen 3.476 N/A GLY 186.A N GLU 185.A OE1 no hydrogen 3.162 N/A THR 188.A N LYS 4.A O no hydrogen 2.952 N/A ALA 189.A N LYS 4.A O no hydrogen 3.197 N/A ILE 190.A N SER 232.A O no hydrogen 2.779 N/A ILE 191.A N LEU 6.A O no hydrogen 2.932 N/A PHE 192.A N ILE 234.A O no hydrogen 2.658 N/A CYS 193.A N LEU 8.A O no hydrogen 2.789 N/A VAL 194.A N PHE 236.A O no hydrogen 2.913 N/A LEU 196.A N ASN 238.A O no hydrogen 2.858 N/A ASP 198.A N ALA 195.A O no hydrogen 2.914 N/A TYR 199.A OH SER 250.A O no hydrogen 2.700 N/A LEU 201.A N ASP 198.A O no hydrogen 3.175 N/A LEU 203.A N MET 209.A O no hydrogen 2.779 N/A GLU 205.A N GLU 205.A OE1 no hydrogen 2.999 N/A ASP 206.A N LEU 203.A O no hydrogen 2.991 N/A GLU 208.A N ASP 206.A OD1 no hydrogen 3.151 N/A ASN 210.A ND2 TYR 199.A O no hydrogen 2.795 N/A ARG 211.A N LEU 201.A O no hydrogen 3.226 N/A ARG 211.A NE VAL 202.A O no hydrogen 3.094 N/A ARG 211.A NH1 GLU 12.A OE1 no hydrogen 3.225 N/A ARG 211.A NH2 GLU 12.A OE1 no hydrogen 2.918 N/A ARG 211.A NH2 GLN 116.A OE1 no hydrogen 3.269 N/A MET 212.A N ASN 210.A OD1 no hydrogen 2.899 N/A HIS 213.A N ASN 210.A OD1 no hydrogen 3.242 N/A HIS 213.A NE2 CYS 255.A O no hydrogen 2.798 N/A GLU 214.A N ASN 210.A O no hydrogen 3.310 N/A SER 215.A N ARG 211.A O no hydrogen 3.134 N/A MET 216.A N MET 212.A O no hydrogen 2.992 N/A LYS 217.A N HIS 213.A O no hydrogen 3.041 N/A LYS 217.A NZ GLU 214.A OE1 no hydrogen 3.126 N/A LEU 218.A N GLU 214.A O no hydrogen 3.068 N/A PHE 219.A N SER 215.A O no hydrogen 2.888 N/A ASP 220.A N MET 216.A O no hydrogen 2.774 N/A SER 221.A N LYS 217.A O no hydrogen 3.059 N/A SER 221.A OG LEU 218.A O no hydrogen 3.108 N/A ILE 222.A N LEU 218.A O no hydrogen 2.865 N/A CYS 223.A N PHE 219.A O no hydrogen 2.763 N/A ASN 224.A N ASP 220.A O no hydrogen 3.314 N/A ASN 224.A ND2 ASP 220.A O no hydrogen 2.847 N/A ASN 224.A ND2 ASP 220.A OD1 no hydrogen 2.746 N/A ASN 224.A ND2 LEU 279.A O no hydrogen 2.801 N/A ASN 225.A N ILE 222.A O no hydrogen 3.135 N/A TRP 227.A N ASN 225.A OD1 no hydrogen 3.204 N/A TRP 227.A NE1 PHE 184.A O no hydrogen 2.434 N/A PHE 228.A N ASN 225.A O no hydrogen 2.793 N/A THR 229.A N LYS 226.A O no hydrogen 3.149 N/A THR 229.A OG1 LYS 226.A O no hydrogen 3.077 N/A THR 231.A N PHE 228.A O no hydrogen 2.981 N/A THR 231.A OG1 VAL 187.A O no hydrogen 2.849 N/A SER 232.A N THR 188.A O no hydrogen 3.356 N/A ILE 234.A N ILE 190.A O no hydrogen 2.680 N/A LEU 235.A N TYR 289.A O no hydrogen 3.034 N/A PHE 236.A N PHE 192.A O no hydrogen 2.729 N/A LEU 237.A N HIS 291.A O no hydrogen 2.875 N/A ASN 238.A N VAL 194.A O no hydrogen 2.706 N/A ASN 238.A ND2 SER 13.A O no hydrogen 2.933 N/A LYS 239.A NZ GLU 12.A O no hydrogen 2.583 N/A LYS 239.A NZ ASP 119.A OD2 no hydrogen 2.447 N/A LYS 240.A N THR 293.A O no hydrogen 2.985 N/A PHE 243.A N LYS 239.A O no hydrogen 3.079 N/A GLU 244.A N LYS 240.A O no hydrogen 2.936 N/A GLU 245.A N ASP 241.A O no hydrogen 3.341 N/A LYS 246.A N LEU 242.A O no hydrogen 2.860 N/A LYS 246.A NZ SER 197.A O no hydrogen 2.705 N/A LYS 246.A NZ ASP 200.A OD1 no hydrogen 2.647 N/A ILE 247.A N PHE 243.A O no hydrogen 2.867 N/A LYS 248.A NZ GLU 245.A OE1 no hydrogen 3.012 N/A LYS 249.A N LYS 246.A O no hydrogen 3.247 N/A LYS 249.A NZ GLU 245.A OE2 no hydrogen 3.401 N/A SER 250.A N LYS 246.A O no hydrogen 3.034 N/A SER 250.A OG ASP 200.A OD2 no hydrogen 2.930 N/A ILE 254.A N PRO 251.A O no hydrogen 3.099 N/A CYS 255.A N LEU 252.A O no hydrogen 2.887 N/A CYS 255.A SG ASN 210.A OD1 no hydrogen 3.537 N/A CYS 255.A SG HIS 213.A NE2 no hydrogen 3.678 N/A TYR 256.A N LEU 252.A O no hydrogen 2.876 N/A TYR 259.A N TYR 256.A O no hydrogen 2.779 N/A TYR 259.A OH SER 262.A O no hydrogen 2.743 N/A SER 262.A N GLU 267.A OE1 no hydrogen 2.971 N/A SER 262.A OG THR 264.A OG1 no hydrogen 3.034 N/A SER 262.A OG GLU 267.A OE2 no hydrogen 2.949 N/A ASN 263.A ND2 LYS 248.A O no hydrogen 3.390 N/A THR 264.A OG1 SER 262.A OG no hydrogen 3.034 N/A ALA 268.A N THR 264.A O no hydrogen 3.043 N/A ALA 269.A N TYR 265.A O no hydrogen 2.904 N/A ALA 270.A N GLU 266.A O no hydrogen 3.336 N/A TYR 271.A N GLU 267.A O no hydrogen 3.177 N/A ILE 272.A N ALA 268.A O no hydrogen 3.106 N/A GLN 273.A N ALA 269.A O no hydrogen 2.984 N/A GLN 273.A NE2 GLU 277.A OE2 no hydrogen 3.242 N/A CYS 274.A N ALA 270.A O no hydrogen 3.089 N/A CYS 274.A SG ALA 270.A O no hydrogen 3.405 N/A GLN 275.A N TYR 271.A O no hydrogen 3.023 N/A PHE 276.A N ILE 272.A O no hydrogen 3.125 N/A GLU 277.A N GLN 273.A O no hydrogen 2.810 N/A ASP 278.A N CYS 274.A O no hydrogen 2.924 N/A LEU 279.A N PHE 276.A O no hydrogen 3.135 N/A ASN 280.A N GLU 277.A O no hydrogen 3.190 N/A ASN 280.A ND2 LYS 286.A O no hydrogen 2.706 N/A LYS 281.A N ASN 224.A OD1 no hydrogen 2.839 N/A LYS 281.A NZ ASP 220.A OD1 no hydrogen 3.091 N/A ARG 282.A N ASN 280.A OD1 no hydrogen 2.999 N/A ARG 282.A NH1 ASN 224.A O no hydrogen 2.771 N/A LYS 283.A NZ ASP 278.A OD1 no hydrogen 3.335 N/A THR 285.A N ARG 282.A O no hydrogen 3.116 N/A LYS 286.A N ARG 282.A O no hydrogen 2.789 N/A LYS 286.A NZ PHE 228.A O no hydrogen 3.391 N/A LYS 286.A NZ THR 229.A O no hydrogen 3.049 N/A LYS 286.A NZ THR 231.A O no hydrogen 2.604 N/A TYR 289.A N ILE 233.A O no hydrogen 2.946 N/A THR 290.A OG1 GLU 277.A OE2 no hydrogen 2.551 N/A HIS 291.A N LEU 235.A O no hydrogen 2.811 N/A THR 293.A N LEU 237.A O no hydrogen 2.938 N/A THR 293.A OG1 ASN 238.A OD1 no hydrogen 2.542 N/A CYS 294.A N ASN 300.A OD1 no hydrogen 2.895 N/A CYS 294.A SG THR 296.A OG1 no hydrogen 3.479 N/A SER 295.A N ASN 238.A OD1 no hydrogen 2.994 N/A SER 295.A OG ASN 238.A OD1 no hydrogen 2.752 N/A ASP 297.A N CYS 294.A O no hydrogen 2.876 N/A THR 298.A OG1 GLN 21.A OE1 no hydrogen 2.910 N/A ASN 300.A N ASP 297.A OD1 no hydrogen 3.134 N/A VAL 301.A N ASP 297.A O no hydrogen 2.988 N/A GLN 302.A N THR 298.A O no hydrogen 2.826 N/A PHE 303.A N LYS 299.A O no hydrogen 3.166 N/A VAL 304.A N ASN 300.A O no hydrogen 3.044 N/A PHE 305.A N VAL 301.A O no hydrogen 2.706 N/A ASP 306.A N GLN 302.A O no hydrogen 2.851 N/A ALA 307.A N PHE 303.A O no hydrogen 3.051 N/A VAL 308.A N VAL 304.A O no hydrogen 2.838 N/A THR 309.A N PHE 305.A O no hydrogen 2.862 N/A THR 309.A OG1 PHE 305.A O no hydrogen 2.865 N/A ASP 310.A N ASP 306.A O no hydrogen 3.284 N/A VAL 311.A N ALA 307.A O no hydrogen 3.262 N/A ILE 312.A N VAL 308.A O no hydrogen 3.048 N/A ILE 313.A N THR 309.A O no hydrogen 2.732 N/A LYS 314.A N ASP 310.A O no hydrogen 2.756 N/A ASN 315.A N VAL 311.A O no hydrogen 2.858 N/A