SEQ2FUN

BioLiP
Download all results in tab-seperated text for 942758 receptor-ligand interactions, whose format is explained at readme.txt.
  • Hover over PDB to view the title of the structure. Click PDB to view the structure at the RCSB PDB database. Resolution -1.00 means the resolution is unavailable, e.g., for NMR structures.
  • Click Site # to view the binding site structure. Hover over Site # to view the binding residues.
  • Hover over Ligand to view the full ligand name. Click Ligand to view the 2D diagram and other detail information of the ligand.
  • Hover over EC number to view the full name of enzymatic activity.
  • Hover over GO terms to view all GO terms.
  • Hover over UniProt to view the protein name.
  • Sort results by
    << < 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 > >>
    Go to page

    # PDB
    (Resolution Å)
    Site # Ligand EC number GO terms UniProt PubMed Binding
    affinity
    376801 5m37:A (2.35) BS01 peptide ? GO:0000122 ... P63104 29039919
    376802 5m37:A (2.35) BS02 9SZ ? GO:0000122 ... P63104 29039919
    376803 5m37:B (2.35) BS01 peptide ? GO:0000122 ... P63104 29039919
    376804 5m37:B (2.35) BS02 9SZ ? GO:0000122 ... P63104 29039919
    376805 5m37:B (2.35) BS03 9SZ ? GO:0000122 ... P63104 29039919
    376806 5m39:A (1.38) BS01 7EA ? N/A O60885 28910100 BindingDB: IC50=24000nM
    376807 5m39:B (1.38) BS01 7EA ? N/A O60885 28910100 BindingDB: IC50=24000nM
    376808 5m3a:A (1.65) BS01 7E7 ? N/A O60885 28910100 BindingDB: IC50=2000nM
    376809 5m3b:A (1.5) BS01 CBY ? GO:0015889 ... P37028 28128319
    376810 5m3b:B (1.5) BS01 CBY ? GO:0015889 ... P37028 28128319
    376811 5m3c:A (2.8) BS01 CA ? N/A Q9I5W1 30106221
    376812 5m3c:A (2.8) BS02 CA ? N/A Q9I5W1 30106221
    376813 5m3c:A (2.8) BS03 CA ? N/A Q9I5W1 30106221
    376814 5m3c:A (2.8) BS04 GTP ? N/A Q9I5W1 30106221
    376815 5m3c:B (2.8) BS01 CA ? N/A Q9I5W1 30106221
    376816 5m3c:B (2.8) BS02 CA ? N/A Q9I5W1 30106221
    376817 5m3c:B (2.8) BS03 GTP ? N/A Q9I5W1 30106221
    376818 5m3e:A (2.5) BS01 APR 3.2.2.- N/A P0DV57 27939941
    376819 5m3f:A (3.8) BS01 dna 2.7.7.6 GO:0000428 ... P10964 27842382
    376820 5m3f:A (3.8) BS02 ZN 2.7.7.6 GO:0000428 ... P10964 27842382
    376821 5m3f:A (3.8) BS03 ZN 2.7.7.6 GO:0000428 ... P10964 27842382
    376822 5m3f:A (3.8) BS04 MG 2.7.7.6 GO:0000428 ... P10964 27842382
    376823 5m3f:B (3.8) BS01 dna 2.7.7.6 GO:0000428 ... P22138 27842382
    376824 5m3f:B (3.8) BS02 rna 2.7.7.6 GO:0000428 ... P22138 27842382
    376825 5m3f:B (3.8) BS03 ZN 2.7.7.6 GO:0000428 ... P22138 27842382
    376826 5m3f:I (3.8) BS01 ZN ? GO:0000122 ... P32529 27842382
    376827 5m3f:J (3.8) BS01 ZN ? GO:0000428 ... P22139 27842382
    376828 5m3f:L (3.8) BS01 ZN ? GO:0000428 ... P40422 27842382
    376829 5m3h:A (2.5) BS01 rna ? GO:0003723 ... H6QM92 28002402
    376830 5m3h:A (2.5) BS02 rna ? GO:0003723 ... H6QM92 28002402
    376831 5m3h:A (2.5) BS03 peptide ? GO:0003723 ... H6QM92 28002402
    376832 5m3h:A (2.5) BS04 peptide ? GO:0003723 ... H6QM92 28002402
    376833 5m3h:B (2.5) BS01 rna 2.7.7.48 GO:0001172 ... H6QM91 28002402
    376834 5m3h:B (2.5) BS02 rna 2.7.7.48 GO:0001172 ... H6QM91 28002402
    376835 5m3h:C (2.5) BS01 rna ? GO:0003723 ... H6QM90 28002402
    376836 5m3j:A (3.5) BS01 rna 3.1.-.- GO:0003723 ... Q5V8Z9 28002402
    376837 5m3j:A (3.5) BS02 rna 3.1.-.- GO:0003723 ... Q5V8Z9 28002402
    376838 5m3j:A (3.5) BS03 peptide 3.1.-.- GO:0003723 ... Q5V8Z9 28002402
    376839 5m3j:B (3.5) BS01 rna 2.7.7.48 GO:0000166 ... Q5V8Y6 28002402
    376840 5m3j:B (3.5) BS02 rna 2.7.7.48 GO:0000166 ... Q5V8Y6 28002402
    376841 5m3j:C (3.5) BS01 rna ? GO:0001172 ... Q5V8X3 28002402
    376842 5m3k:B (2.83) BS01 ZN ? GO:0046872 ... Q4K419 30318713
    376843 5m3k:E (2.83) BS01 ZN ? GO:0046872 ... Q4K419 30318713
    376844 5m3l:A (3.8) BS01 HEM ? GO:0005344 ... P13579 28989723
    376845 5m3l:B (3.8) BS01 HEM ? GO:0005344 ... P02218 28989723
    376846 5m3l:C (3.8) BS01 HEM ? GO:0005344 ... P11069 28989723
    376847 5m3l:D (3.8) BS01 HEM ? GO:0005344 ... O61233 28989723
    376848 5m3l:E (3.8) BS01 HEM ? GO:0005344 ... P13579 28989723
    376849 5m3l:F (3.8) BS01 HEM ? GO:0005344 ... P02218 28989723
    376850 5m3l:G (3.8) BS01 HEM ? GO:0005344 ... P11069 28989723
    376851 5m3l:H (3.8) BS01 HEM ? GO:0005344 ... O61233 28989723
    376852 5m3l:I (3.8) BS01 HEM ? GO:0005344 ... P13579 28989723
    376853 5m3l:J (3.8) BS01 HEM ? GO:0005344 ... P02218 28989723
    376854 5m3l:K (3.8) BS01 HEM ? GO:0005344 ... P11069 28989723
    376855 5m3l:L (3.8) BS01 HEM ? GO:0005344 ... O61233 28989723
    376856 5m3m:A (4.0) BS01 ZN 2.7.7.6 GO:0000428 ... P10964 27842382
    376857 5m3m:A (4.0) BS02 ZN 2.7.7.6 GO:0000428 ... P10964 27842382
    376858 5m3m:B (4.0) BS01 ZN 2.7.7.6 GO:0000428 ... P22138 27842382
    376859 5m3m:I (4.0) BS01 ZN ? GO:0000122 ... P32529 27842382
    376860 5m3m:I (4.0) BS02 ZN ? GO:0000122 ... P32529 27842382
    376861 5m3m:J (4.0) BS01 ZN ? GO:0000428 ... P22139 27842382
    376862 5m3m:L (4.0) BS01 ZN ? GO:0000428 ... P40422 27842382
    376863 5m3s:A (1.8) BS01 HEM 1.11.1.-
    1.7.-.-
    GO:0004601 ... P02185 28375148
    376864 5m3u:A (1.81) BS01 ADP 2.7.2.3 GO:0004618 ... P00558 29995887
    376865 5m3u:A (1.81) BS02 MG 2.7.2.3 GO:0004618 ... P00558 29995887
    376866 5m3v:A (1.97) BS01 BMA ? N/A P01857
    P01860
    28450393
    376867 5m3v:A (1.97) BS02 GAL ? N/A P01857
    P01860
    28450393
    376868 5m3v:B (1.97) BS01 GAL ? N/A P01857 28450393
    376869 5m3w:A (1.04) BS01 7D1 ? GO:0004559 ... D6D1V7 27992199
    376870 5m3w:A (1.04) BS02 MAN ? GO:0004559 ... D6D1V7 27992199
    376871 5m3w:A (1.04) BS03 MAN ? GO:0004559 ... D6D1V7 27992199
    376872 5m3w:A (1.04) BS04 MAN ? GO:0004559 ... D6D1V7 27992199
    376873 5m3z:A (1.45) BS01 PLP 4.4.1.11 GO:0005737 ... A0A0A5P8W7 28602917
    376874 5m3z:A (1.45) BS02 NLE 4.4.1.11 GO:0005737 ... A0A0A5P8W7 28602917 MOAD: Ki=0.6mM
    376875 5m3z:A (1.45) BS03 PY6 4.4.1.11 GO:0005737 ... A0A0A5P8W7 28602917
    376876 5m41:A (2.1) BS01 MG N/A N/A N/A 29093459
    376877 5m42:A (2.2) BS01 FMN 1.5.5.2 GO:0004657 ... Q72IB8 28256579 MOAD: Kd=19.5nM
    376878 5m44:A (2.71) BS01 7EY 2.7.11.1 GO:0004672 ... P68400 28085026
    376879 5m45:A (1.87) BS01 MN 6.4.1.6 GO:0003824 ... Q8RM03 28775283
    376880 5m45:A (1.87) BS02 ACT 6.4.1.6 GO:0003824 ... Q8RM03 28775283
    376881 5m45:A (1.87) BS03 MG 6.4.1.6 GO:0003824 ... Q8RM03 28775283
    376882 5m45:B (1.87) BS01 AMP 6.4.1.6 GO:0005524 ... Q8RM04 28775283
    376883 5m45:B (1.87) BS02 MG 6.4.1.6 GO:0005524 ... Q8RM04 28775283
    376884 5m45:B (1.87) BS03 ACT 6.4.1.6 GO:0005524 ... Q8RM04 28775283
    376885 5m45:C (1.87) BS01 ZN 6.4.1.6 GO:0005524 ... Q8RM02 28775283
    376886 5m45:D (1.87) BS01 MN 6.4.1.6 GO:0003824 ... Q8RM03 28775283
    376887 5m45:D (1.87) BS02 ACT 6.4.1.6 GO:0003824 ... Q8RM03 28775283
    376888 5m45:D (1.87) BS03 MG 6.4.1.6 GO:0003824 ... Q8RM03 28775283
    376889 5m45:E (1.87) BS01 AMP 6.4.1.6 GO:0005524 ... Q8RM04 28775283
    376890 5m45:E (1.87) BS02 MG 6.4.1.6 GO:0005524 ... Q8RM04 28775283
    376891 5m45:E (1.87) BS03 ACT 6.4.1.6 GO:0005524 ... Q8RM04 28775283
    376892 5m45:F (1.87) BS01 ZN 6.4.1.6 GO:0005524 ... Q8RM02 28775283
    376893 5m45:G (1.87) BS01 MN 6.4.1.6 GO:0003824 ... Q8RM03 28775283
    376894 5m45:G (1.87) BS02 ACT 6.4.1.6 GO:0003824 ... Q8RM03 28775283
    376895 5m45:G (1.87) BS03 MG 6.4.1.6 GO:0003824 ... Q8RM03 28775283
    376896 5m45:H (1.87) BS01 AMP 6.4.1.6 GO:0005524 ... Q8RM04 28775283
    376897 5m45:H (1.87) BS02 MG 6.4.1.6 GO:0005524 ... Q8RM04 28775283
    376898 5m45:H (1.87) BS03 ACT 6.4.1.6 GO:0005524 ... Q8RM04 28775283
    376899 5m45:I (1.87) BS01 ZN 6.4.1.6 GO:0005524 ... Q8RM02 28775283
    376900 5m45:J (1.87) BS01 MN 6.4.1.6 GO:0003824 ... Q8RM03 28775283
    376901 5m45:J (1.87) BS02 ACT 6.4.1.6 GO:0003824 ... Q8RM03 28775283
    376902 5m45:J (1.87) BS03 MG 6.4.1.6 GO:0003824 ... Q8RM03 28775283
    376903 5m45:K (1.87) BS01 AMP 6.4.1.6 GO:0005524 ... Q8RM04 28775283
    376904 5m45:K (1.87) BS02 MG 6.4.1.6 GO:0005524 ... Q8RM04 28775283
    376905 5m45:K (1.87) BS03 ACT 6.4.1.6 GO:0005524 ... Q8RM04 28775283
    376906 5m45:L (1.87) BS01 ZN 6.4.1.6 GO:0005524 ... Q8RM02 28775283
    376907 5m46:A (1.62) BS01 PLP ? GO:0008483 ... N6UXY4 N/A
    376908 5m47:A (2.59) BS01 API 5.1.1.7 GO:0005737 ... Q8NP73 28176858
    376909 5m49:A (1.51) BS01 PLP ? GO:0008483 ... N6UXY4 N/A
    376910 5m49:A (1.51) BS02 8F4 ? GO:0008483 ... N6UXY4 N/A
    376911 5m49:A (1.51) BS03 7F4 ? GO:0008483 ... N6UXY4 N/A
    376912 5m4a:A (2.9) BS01 GLC 3.2.1.28 GO:0004555 ... P32356 29087344
    376913 5m4a:A (2.9) BS02 GLC 3.2.1.28 GO:0004555 ... P32356 29087344
    376914 5m4b:A (1.5) BS01 7F7 5.1.1.15 GO:0008483 ... N6UXY4 N/A
    376915 5m4c:A (1.935) BS01 7EY 2.7.11.1 GO:0004672 ... P68400 28085026
    376916 5m4d:A (1.93) BS01 7F7 ? GO:0008483 ... N6UXY4 N/A
    376917 5m4e:A (1.9) BS01 7F9 3.6.4.10 GO:0005524 ... P07900 28199108
    376918 5m4f:A (1.519) BS01 7FC 2.7.11.1 GO:0004672 ... P68400 28085026
    376919 5m4g:A (1.48) BS01 MN 3.4.13.9 GO:0004181 ... P12955 28677335
    376920 5m4g:A (1.48) BS02 MN 3.4.13.9 GO:0004181 ... P12955 28677335
    376921 5m4g:A (1.48) BS03 OH 3.4.13.9 GO:0004181 ... P12955 28677335
    376922 5m4g:B (1.48) BS01 MN 3.4.13.9 GO:0004181 ... P12955 28677335
    376923 5m4g:B (1.48) BS02 MN 3.4.13.9 GO:0004181 ... P12955 28677335
    376924 5m4g:B (1.48) BS03 OH 3.4.13.9 GO:0004181 ... P12955 28677335
    376925 5m4h:A (2.0) BS01 7FX 3.6.4.10 GO:0005524 ... P07900 28199108
    376926 5m4i:A (2.218) BS01 7FC 2.7.11.1 GO:0004672 ... P68400 28085026
    376927 5m4j:A (1.55) BS01 GLY 3.4.13.9 GO:0004181 ... P12955 28677335
    376928 5m4j:A (1.55) BS02 PRO 3.4.13.9 GO:0004181 ... P12955 28677335
    376929 5m4j:B (1.55) BS01 GLY 3.4.13.9 GO:0004181 ... P12955 28677335
    376930 5m4j:B (1.55) BS02 PRO 3.4.13.9 GO:0004181 ... P12955 28677335
    376931 5m4k:A (2.6) BS01 TF3 2.7.11.2 GO:0004672 ... Q15119 28199108 BindingDB: IC50=2000nM
    376932 5m4k:A (2.6) BS02 7F9 2.7.11.2 GO:0004672 ... Q15119 28199108 BindingDB: IC50=4460nM, Ki=2170nM
    376933 5m4l:A (1.49) BS01 MG 3.4.13.9 GO:0004181 ... P12955 28677335
    376934 5m4l:A (1.49) BS02 MG 3.4.13.9 GO:0004181 ... P12955 28677335
    376935 5m4l:A (1.49) BS03 OH 3.4.13.9 GO:0004181 ... P12955 28677335
    376936 5m4l:A (1.49) BS04 LEU 3.4.13.9 GO:0004181 ... P12955 28677335
    376937 5m4l:A (1.49) BS05 PRO 3.4.13.9 GO:0004181 ... P12955 28677335
    376938 5m4l:B (1.49) BS01 MG 3.4.13.9 GO:0004181 ... P12955 28677335
    376939 5m4l:B (1.49) BS02 MG 3.4.13.9 GO:0004181 ... P12955 28677335
    376940 5m4l:B (1.49) BS03 OH 3.4.13.9 GO:0004181 ... P12955 28677335
    376941 5m4l:B (1.49) BS04 LEU 3.4.13.9 GO:0004181 ... P12955 28677335
    376942 5m4l:B (1.49) BS05 PRO 3.4.13.9 GO:0004181 ... P12955 28677335
    376943 5m4m:A (2.4) BS01 7FW 2.7.11.2 GO:0004672 ... Q15119 28199108 MOAD: Ki=1.02uM
    376944 5m4m:A (2.4) BS02 TF3 2.7.11.2 GO:0004672 ... Q15119 28199108 BindingDB: IC50=2000nM
    376945 5m4n:A (2.6) BS01 7FV 2.7.11.2 GO:0004672 ... Q15119 28199108
    376946 5m4n:A (2.6) BS02 TF3 2.7.11.2 GO:0004672 ... Q15119 28199108 BindingDB: IC50=2000nM
    376947 5m4o:B (2.1) BS01 FE 1.13.11.- GO:0046872 ... F8TW83 28232026
    376948 5m4o:B (2.1) BS02 NPO 1.13.11.- GO:0046872 ... F8TW83 28232026
    376949 5m4o:D (2.1) BS01 FE 1.13.11.- GO:0046872 ... F8TW83 28232026
    376950 5m4o:D (2.1) BS02 NPO 1.13.11.- GO:0046872 ... F8TW83 28232026
    376951 5m4o:F (2.1) BS01 FE 1.13.11.- GO:0046872 ... F8TW83 28232026
    376952 5m4o:F (2.1) BS02 NPO 1.13.11.- GO:0046872 ... F8TW83 28232026
    376953 5m4o:H (2.1) BS01 FE 1.13.11.- GO:0046872 ... F8TW83 28232026
    376954 5m4o:H (2.1) BS02 NPO 1.13.11.- GO:0046872 ... F8TW83 28232026
    376955 5m4p:A (2.3) BS01 7FE 2.7.11.2 GO:0004672 ... Q15119 28199108
    376956 5m4p:A (2.3) BS02 TF3 2.7.11.2 GO:0004672 ... Q15119 28199108 BindingDB: IC50=2000nM
    376957 5m4q:A (1.73) BS01 MN 3.4.13.9 GO:0004181 ... P12955 28677335
    376958 5m4q:A (1.73) BS02 MN 3.4.13.9 GO:0004181 ... P12955 28677335
    376959 5m4q:A (1.73) BS03 OH 3.4.13.9 GO:0004181 ... P12955 28677335
    376960 5m4q:A (1.73) BS04 PRO 3.4.13.9 GO:0004181 ... P12955 28677335 MOAD: Ki=0.31mM
    376961 5m4q:B (1.73) BS01 MN 3.4.13.9 GO:0004181 ... P12955 28677335
    376962 5m4q:B (1.73) BS02 MN 3.4.13.9 GO:0004181 ... P12955 28677335
    376963 5m4q:B (1.73) BS03 OH 3.4.13.9 GO:0004181 ... P12955 28677335
    376964 5m4q:B (1.73) BS04 PRO 3.4.13.9 GO:0004181 ... P12955 28677335 MOAD: Ki=0.31mM
    376965 5m4u:A (2.195) BS01 7FC 2.7.11.1 GO:0000785 ... P19784 28085026
    376966 5m4z:A (1.179) BS01 7K8 2.1.1.45 GO:0004799 ... Q9NDD3 33946210
    376967 5m4z:A (1.179) BS02 7K8 2.1.1.45 GO:0004799 ... Q9NDD3 33946210
    376968 5m4z:B (1.179) BS01 7K8 2.1.1.45 GO:0004799 ... Q9NDD3 33946210
    376969 5m4z:B (1.179) BS02 7K8 2.1.1.45 GO:0004799 ... Q9NDD3 33946210
    376970 5m50:A (5.3) BS01 GTP 3.6.5.- GO:0000226 ... P81947 28991265
    376971 5m50:B (5.3) BS01 GDP ? GO:0000226 ... Q6B856 28991265
    376972 5m50:B (5.3) BS02 TA1 ? GO:0000226 ... Q6B856 28991265
    376973 5m50:D (5.3) BS01 GTP 3.6.5.- GO:0000226 ... P81947 28991265
    376974 5m50:E (5.3) BS01 GDP ? GO:0000226 ... Q6B856 28991265
    376975 5m50:E (5.3) BS02 TA1 ? GO:0000226 ... Q6B856 28991265
    376976 5m51:A (1.899) BS01 NU6 2.7.11.1 GO:0004672 ... P51955 27833088 MOAD: ic50=19uM
    376977 5m53:A (1.9) BS01 7GJ 2.7.11.1 GO:0004672 ... P51955 27833088 MOAD: ic50=0.62uM
    376978 5m54:A (8.0) BS01 GTP 3.6.5.- GO:0000226 ... P81947 28991265
    376979 5m54:A (8.0) BS02 MG 3.6.5.- GO:0000226 ... P81947 28991265
    376980 5m54:B (8.0) BS01 GDP ? GO:0000226 ... Q6B856 28991265
    376981 5m54:B (8.0) BS02 TA1 ? GO:0000226 ... Q6B856 28991265
    376982 5m54:D (8.0) BS01 GTP 3.6.5.- GO:0000226 ... P81947 28991265
    376983 5m54:D (8.0) BS02 MG 3.6.5.- GO:0000226 ... P81947 28991265
    376984 5m54:E (8.0) BS01 GDP ? GO:0000226 ... Q6B856 28991265
    376985 5m54:E (8.0) BS02 TA1 ? GO:0000226 ... Q6B856 28991265
    376986 5m55:A (2.4) BS01 7GG 2.7.11.1 GO:0004672 ... P51955 27833088 MOAD: ic50=0.24uM
    376987 5m56:A (2.237) BS01 7FC 2.7.11.1 GO:0000785 ... P19784 28085026
    376988 5m56:B (2.237) BS01 7FC 2.7.11.1 GO:0000785 ... P19784 28085026
    376989 5m57:A (2.3) BS01 4SP 2.7.11.1 GO:0004672 ... P51955 27833088 MOAD: ic50=12uM
    376990 5m58:A (2.05) BS01 SAH 2.1.1.- GO:0008168 ... Q9F8T9 28152088
    376991 5m58:B (2.05) BS01 SAH 2.1.1.- GO:0008168 ... Q9F8T9 28152088
    376992 5m5a:A (1.9) BS01 KSA 2.7.10.2
    2.7.11.1
    GO:0004672 ... Q14680 29191878
    376993 5m5b:A (2.01) BS01 SAM 2.1.1.56
    2.1.1.57
    2.7.7.48
    3.4.21.91
    3.6.1.15
    3.6.4.13
    GO:0004482 ... A0A024B7W1 28031359
    376994 5m5b:A (2.01) BS02 SO4 2.1.1.56
    2.1.1.57
    2.7.7.48
    3.4.21.91
    3.6.1.15
    3.6.4.13
    GO:0004482 ... A0A024B7W1 28031359
    376995 5m5b:A (2.01) BS03 SO4 2.1.1.56
    2.1.1.57
    2.7.7.48
    3.4.21.91
    3.6.1.15
    3.6.4.13
    GO:0004482 ... A0A024B7W1 28031359
    376996 5m5b:B (2.01) BS01 GOL 2.1.1.56
    2.1.1.57
    2.7.7.48
    3.4.21.91
    3.6.1.15
    3.6.4.13
    GO:0004482 ... A0A024B7W1 28031359
    376997 5m5c:A (4.8) BS01 GTP 3.6.5.- GO:0000226 ... P81947 28991265
    376998 5m5c:B (4.8) BS01 GDP ? GO:0000226 ... Q6B856 28991265
    376999 5m5c:B (4.8) BS02 TA1 ? GO:0000226 ... Q6B856 28991265
    377000 5m5c:D (4.8) BS01 GTP 3.6.5.- GO:0000226 ... P81947 28991265

    Reference:
  • Chengxin Zhang, Xi Zhang, Lydia Freddolino, and Yang Zhang. BioLiP2: an updated structure database for biologically relevent ligand-protein interactions, Nucleic Acids Research, gkad630 (2023).
  • Jianyi Yang, Ambrish Roy, and Yang Zhang. BioLiP: a semi-manually curated database for biologically relevant ligand-protein interactions, Nucleic Acids Research, 41: D1096-D1103 (2013) (download the PDF file).