HEADER TOXIN 15-JAN-88 3EBX 3EBX 3 COMPND ERABUTOXIN $B 3EBX 4 SOURCE SEA SNAKE (LATICAUDA $SEMIFASCIATA) VENOM 3EBX 5 AUTHOR J.L.SMITH,P.W.R.CORFIELD,W.A.HENDRICKSON,B.W.LOW 3EBX 6 REVDAT 2 09-OCT-88 3EBXA 1 JRNL 3EBXA 1 REVDAT 1 16-APR-88 3EBX 0 3EBX 7 SPRSDE 16-APR-88 3EBX 2EBX 3EBX 8 JRNL AUTH J.L.SMITH,P.W.R.CORFIELD,W.A.HENDRICKSON,B.W.LOW 3EBX 9 JRNL TITL REFINEMENT AT 1.4 ANGSTROMS RESOLUTION OF A MODEL 3EBX 10 JRNL TITL 2 OF ERABUTOXIN $B. TREATMENT OF ORDERED SOLVENT AND 3EBX 11 JRNL TITL 3 DISCRETE DISORDER 3EBX 12 JRNL REF ACTA CRYSTALLOGR.,SECT.A V. 44 357 1988 3EBXA 2 JRNL REFN ASTM ACACEQ DK ISSN 0108-7673 621 3EBXA 3 REMARK 1 3EBX 15 REMARK 1 REFERENCE 1 3EBX 16 REMARK 1 AUTH B.W.LOW,P.W.R.CORFIELD 3EBX 17 REMARK 1 TITL ACETYLCHOLINE RECEPTOR. ALPHA-TOXIN BINDING SITE - 3EBX 18 REMARK 1 TITL THEORETICAL AND MODEL STUDIES 3EBX 19 REMARK 1 REF ASIA PAC.J.PHARMACOL. V. 2 115 1987 3EBX 20 REMARK 1 REFN ASTM APJPEV SI ISSN 0217-9687 852 3EBX 21 REMARK 1 REFERENCE 2 3EBX 22 REMARK 1 AUTH B.W.LOW,P.W.R.CORFIELD 3EBX 23 REMARK 1 TITL ERABUTOXIN $B. STRUCTURE(SLASH)FUNCTION 3EBX 24 REMARK 1 TITL 2 RELATIONSHIPS FOLLOWING INITIAL PROTEIN REFINEMENT 3EBX 25 REMARK 1 TITL 3 AT 0.140-NM RESOLUTION 3EBX 26 REMARK 1 REF EUR.J.BIOCHEM. V. 161 579 1986 3EBX 27 REMARK 1 REFN ASTM EJBCAI IX ISSN 0014-2956 262 3EBX 28 REMARK 1 REFERENCE 3 3EBX 29 REMARK 1 AUTH P.E.BOURNE,A.SATO,P.W.R.CORFIELD,L.S.ROSEN, 3EBX 30 REMARK 1 AUTH 2 S.BIRKEN,B.W.LOW 3EBX 31 REMARK 1 TITL ERABUTOXIN $B. INITIAL PROTEIN REFINEMENT AND 3EBX 32 REMARK 1 TITL SEQUENCE ANALYSIS AT 0.140-NM RESOLUTION 3EBX 33 REMARK 1 REF EUR.J.BIOCHEM. V. 153 521 1985 3EBX 34 REMARK 1 REFN ASTM EJBCAI IX ISSN 0014-2956 262 3EBX 35 REMARK 1 REFERENCE 4 3EBX 36 REMARK 1 AUTH J.DRENTH,B.W.LOW,J.S.RICHARDSON,C.S.WRIGHT 3EBX 37 REMARK 1 TITL THE TOXIN-*AGGLUTININ FOLD. A NEW GROUP OF SMALL 3EBX 38 REMARK 1 TITL 2 PROTEIN STRUCTURES ORGANIZED AROUND A 3EBX 39 REMARK 1 TITL 3 FOUR-DISULFIDE CORE 3EBX 40 REMARK 1 REF J.BIOL.CHEM. V. 255 2652 1980 3EBX 41 REMARK 1 REFN ASTM JBCHA3 US ISSN 0021-9258 071 3EBX 42 REMARK 1 REFERENCE 5 3EBX 43 REMARK 1 AUTH M.R.KIMBALL,A.SATO,J.S.RICHARDSON,L.S.ROSEN,B.W.LOW 3EBX 44 REMARK 1 TITL MOLECULAR CONFORMATION OF ERABUTOXIN $B. ATOMIC 3EBX 45 REMARK 1 TITL 2 COORDINATES AT 2.5 ANGSTROMS RESOLUTION 3EBX 46 REMARK 1 REF BIOCHEM.BIOPHYS.RES.COMM. V. 88 950 1979 3EBX 47 REMARK 1 REFN ASTM BBRCA9 US ISSN 0006-291X 146 3EBX 48 REMARK 1 REFERENCE 6 3EBX 49 REMARK 1 AUTH B.W.LOW 3EBX 50 REMARK 1 TITL THE THREE-*DIMENSIONAL STRUCTURE OF POSTSYNAPTIC 3EBX 51 REMARK 1 TITL 2 SNAKE NEUROTOXINS. CONSIDERATION OF STRUCTURE AND 3EBX 52 REMARK 1 TITL 3 FUNCTION 3EBX 53 REMARK 1 REF HANDB.EXP.PHARMACOL. V. 52 213 1979 3EBX 54 REMARK 1 REFN ASTM HEPHD2 GW ISSN 0171-2004 884 3EBX 55 REMARK 1 REFERENCE 7 3EBX 56 REMARK 1 AUTH B.W.LOW,H.S.PRESTON,A.SATO,L.S.ROSEN,J.E.SEARL, 3EBX 57 REMARK 1 AUTH 2 A.D.RUDKO,J.S.RICHARDSON 3EBX 58 REMARK 1 TITL THREE DIMENSIONAL STRUCTURE OF ERABUTOXIN $B 3EBX 59 REMARK 1 TITL 2 NEUROTOXIC PROTEIN. INHIBITOR OF ACETYLCHOLINE 3EBX 60 REMARK 1 TITL 3 RECEPTOR 3EBX 61 REMARK 1 REF PROC.NAT.ACAD.SCI.USA V. 73 2991 1976 3EBX 62 REMARK 1 REFN ASTM PNASA6 US ISSN 0027-8424 040 3EBX 63 REMARK 1 REFERENCE 8 3EBX 64 REMARK 1 AUTH B.W.LOW,R.POTTER,R.B.JACKSON,N.TAMIYA,S.SATO 3EBX 65 REMARK 1 TITL X-RAY CRYSTALLOGRAPHIC STUDY OF THE ERABUTOXINS AND 3EBX 66 REMARK 1 TITL 2 OF A DIIODO DERIVATIVE 3EBX 67 REMARK 1 REF J.BIOL.CHEM. V. 246 4366 1971 3EBX 68 REMARK 1 REFN ASTM JBCHA3 US ISSN 0021-9258 071 3EBX 69 REMARK 2 3EBX 70 REMARK 2 RESOLUTION. 1.4 ANGSTROMS. 3EBX 71 REMARK 3 3EBX 72 REMARK 3 REFINEMENT. BY THE RESTRAINED LEAST-SQUARES PROCEDURE OF J. 3EBX 73 REMARK 3 KONNERT AND W. HENDRICKSON (PROGRAM *PROLSQ*). THE 3EBX 74 REMARK 3 STARTING COORDINATES WERE THOSE OF P. BOURNE ET AL. 3EBX 75 REMARK 3 (PREVIOUSLY DISTRIBUTED BY THE PROTEIN DATA BANK AS ENTRY 3EBX 76 REMARK 3 *2EBX*). THE R VALUE IS 0.14 FOR 7732 REFLECTIONS WITH 3EBX 77 REMARK 3 FOBS**2 .GT. 2.0*SIGMA(FOBS)**2, REPRESENTING 74 PER CENT 3EBX 78 REMARK 3 OF THE TOTAL AVAILABLE DATA IN THE RESOLUTION RANGE 10.0 3EBX 79 REMARK 3 TO 1.4 ANGSTROMS. (THE R VALUE IS 0.176 FOR ALL 10405 3EBX 80 REMARK 3 REFLECTIONS IN THIS SAME RANGE). THE RMS DEVIATION FROM 3EBX 81 REMARK 3 IDEALITY OF THE BOND LENGTHS IS 0.016 ANGSTROMS. THE RMS 3EBX 82 REMARK 3 DEVIATION FROM IDEALITY OF THE BOND ANGLES IS 1.5 DEGREES. 3EBX 83 REMARK 4 3EBX 84 REMARK 4 IN THIS STAGE OF THE REFINEMENT, EMPHASIS WAS ON DEFINING 3EBX 85 REMARK 4 DISORDERED GROUPS WITHIN THE PROTEIN AND ON EXTENDING THE 3EBX 86 REMARK 4 DESCRIPTION OF THE SOLVENT STRUCTURE. THE FINAL MODEL 3EBX 87 REMARK 4 INCLUDES A TOTAL OF 111 SITES FOR WATER MOLECULES WITH 3EBX 88 REMARK 4 OCCUPANCY FACTORS RANGING FROM 0.3 TO 1.0. THE SUM OF ALL 3EBX 89 REMARK 4 WATER OCCUPANCY FACTORS EQUALS 65. ONE HALF-WEIGHT SULFATE 3EBX 90 REMARK 4 ION ALSO WAS LOCATED. SOLVENT NUMBERING HERE CORRESPONDS 3EBX 91 REMARK 4 TO THAT PRESENTED IN THE *JRNL* REFERENCE ABOVE. FOR THE 3EBX 92 REMARK 4 PROTEIN, THE FINAL MODEL INCLUDES TWO WELL-DEFINED 3EBX 93 REMARK 4 CONFORMERS FOR EACH OF SEVEN SIDE CHAINS, AND TWO LESS 3EBX 94 REMARK 4 WELL-DEFINED CONFORMERS FOR THE OCTAPEPTIDE SEGMENT 44-51. 3EBX 95 REMARK 5 3EBX 96 REMARK 5 SHIFTS FROM ENTRY *2EBX* IN POSITIONS OF NON-DISORDERED 3EBX 97 REMARK 5 PROTEIN ATOMS ARE VERY SMALL. THE RMS DEVIATION IS 0.5 3EBX 98 REMARK 5 ANGSTROMS FOR ALL NON-DISORDERED ATOMS AND 0.07 ANGSTROMS 3EBX 99 REMARK 5 FOR MAIN CHAIN ATOMS. 3EBX 100 REMARK 6 3EBX 101 REMARK 6 THE PREVIOUS REFINEMENT ESTABLISHED THE STRUCTURAL IDENTITY 3EBX 102 REMARK 6 OF ERABUTOXIN B AND NEUROTOXIN B. ERABUTOXIN B WAS 3EBX 103 REMARK 6 ISOLATED FROM THE VENOM OF LATICAUDA SEMIFASCIATA FOUND OFF 3EBX 104 REMARK 6 THE OKINAWAS (RYUKU ISLANDS). NEUROTOXIN B WAS ALSO 3EBX 105 REMARK 6 ISOLATED FROM THE VENOM OF LATICAUDA SEMIFASCIATA BUT FOUND 3EBX 106 REMARK 6 IN DIFFERENT PACIFIC OCEAN WATERS. PREVIOUS CHEMICAL 3EBX 107 REMARK 6 SEQUENCE ERRORS IN THESE TOXINS AT HIS 6-GLU 7 AND 3EBX 108 REMARK 6 SER 18-PRO 19 WERE CORRECTED IN ENTRY *2EBX*. THE CHEMICAL 3EBX 109 REMARK 6 DESIGNATION VAL 59 (CITED AS ARG 59 IN NEUROTOXIN B) WAS 3EBX 110 REMARK 6 ALSO UNAMBIGUOUSLY VERIFED. 3EBX 111 REMARK 7 3EBX 112 REMARK 7 THE POSTSYNAPTIC NEUROTOXINS OF SEA SNAKE VENOM ARE 3EBX 113 REMARK 7 ANTAGONISTS OF THE NICOTINIC ACETYLCHOLINE RECEPTOR. THE 3EBX 114 REMARK 7 HOMOLOGY BETWEEN ALL THESE VENOM NEUROTOXINS OF BOTH SHORT 3EBX 115 REMARK 7 AND LONG CHAIN SERIES IS ACKNOWLEDGED IN SOME PUBLICATIONS 3EBX 116 REMARK 7 BY SEQUENCE NUMBER CHANGES (SEE REFERENCE 6 ABOVE FOR 3EBX 117 REMARK 7 DETAILS). 3EBX 118 REMARK 8 3EBX 119 REMARK 8 THE FEATURES OF THE REACTIVE SITE OF ERABUTOXIN B ESTABLISH 3EBX 120 REMARK 8 IT AS A VALID PROTOTYPE FOR ALL THE POSTSYNAPTIC 3EBX 121 REMARK 8 NEUROTOXINS OF THIS SNAKE VENOM SERIES. SITE *RCT* BELOW 3EBX 122 REMARK 8 PRESENTS THE SERIES INVARIANT RESIDUES OF THE REACTIVE 3EBX 123 REMARK 8 SITE. FIVE OF THESE RESIDUES (PHE 32, ILE 36, GLU 38, ILE 3EBX 124 REMARK 8 50, LEU 52) ARE TYPE-CONSERVED THROUGHOUT THE SERIES. THE 3EBX 125 REMARK 8 ENUMERATION IS FOR A 62-RESIDUE TOXIN. SITE *FNR* BELOW 3EBX 126 REMARK 8 PRESENTS THE RESIDUES IN THE REACTIVE SITE SHOWN CHEMICALLY 3EBX 127 REMARK 8 TO BIND DIRECTLY TO RECEPTOR. SITE *CMR* PRESENTS THE 3EBX 128 REMARK 8 RESIDUES, INCLUDING FOUR CYSTINE LINKAGES, WHICH AID IN 3EBX 129 REMARK 8 MAINTAINING THE UNIQUE TOXIN FOLD CONFORMATION. ALL 3EBX 130 REMARK 8 RESIDUES PRESENTED ON *SITE* RECORDS BELOW ARE 3EBX 131 REMARK 8 COMMON-INVARIANT OR TYPE-CONSERVED HOMOLOGOUS SERIES 3EBX 132 REMARK 8 RESIDUES, EXCEPT GLY 42. (IN THE LONG SERIES, INVARIANT 3EBX 133 REMARK 8 GLY 42 IS SUBSTITUTED BY INVARIANT ALA, ALA, THR.) 3EBX 134 REMARK 9 3EBX 135 REMARK 9 ONLY MAIN-CHAIN TO MAIN-CHAIN HYDROGEN BONDS ARE PRESENTED 3EBX 136 REMARK 9 ON THE *CONECT* RECORDS BELOW. SALT BRIDGES, MAIN-CHAIN TO 3EBX 137 REMARK 9 SIDE-CHAIN, SIDE-CHAIN TO SIDE-CHAIN AND HYDROGEN BONDS 3EBX 138 REMARK 9 INVOLVING WATER MOLECULES ARE NOT INCLUDED. 3EBX 139 REMARK 9 THE RANGE OF N-H...O DISTANCES IS 2.77 TO 3.21 ANGSTROMS. 3EBX 140 REMARK 9 THE MEAN OF N-H...O IN BETA TURNS IS 3.15 ANGSTROMS. 3EBX 141 REMARK 9 THE MEAN OF N-H...O NOT IN TURNS IS 2.91 ANGSTROMS. 3EBX 142 REMARK 10 3EBX 143 REMARK 10 THE BETA SHEET *DCE* WAS INADVERTENTLY NOT INCLUDED IN 3EBX 144 REMARK 10 ENTRY *2EBX*. 3EBX 145 REMARK 11 3EBXA 4 REMARK 11 CORRECTION. UPDATE JRNL REFERENCE TO REFLECT PUBLICATION. 3EBXA 5 REMARK 11 09-OCT-88. 3EBXA 6 SEQRES 1 62 ARG ILE CYS PHE ASN HIS GLN SER SER GLN PRO GLN THR 3EBX 146 SEQRES 2 62 THR LYS THR CYS SER PRO GLY GLU SER SER CYS TYR HIS 3EBX 147 SEQRES 3 62 LYS GLN TRP SER ASP PHE ARG GLY THR ILE ILE GLU ARG 3EBX 148 SEQRES 4 62 GLY CYS GLY CYS PRO THR VAL LYS PRO GLY ILE LYS LEU 3EBX 149 SEQRES 5 62 SER CYS CYS GLU SER GLU VAL CYS ASN ASN 3EBX 150 FTNOTE 1 3EBX 151 FTNOTE 1 SEE REMARK 4. 3EBX 152 HET SO4 1 5 SULFATE ION 3EBX 153 FORMUL 2 SO4 O4 S1 -- 3EBX 154 FORMUL 3 HOH *111(H2 O1) 3EBX 155 SHEET 1 AB 2 ARG 1 ASN 5 0 3EBX 156 SHEET 2 AB 2 THR 13 CYS 17 -1 O LYS 15 N CYS 3 3EBX 157 SHEET 1 DCE 3 GLY 34 CYS 41 0 3EBX 158 SHEET 2 DCE 3 SER 23 ASP 31 -1 N TYR 25 O GLY 40 3EBX 159 SHEET 3 DCE 3 ILE 50 CYS 55 -1 O SER 53 N HIS 26 3EBX 160 TURN 1 T1 GLN 7 GLN 10 TYPE II(PRIME) BEND 3EBX 161 TURN 2 T2 SER 18 GLU 21 TYPE II BEND 3EBX 162 TURN 3 T3 ASP 31 GLY 34 TYPE I/III BEND 3EBX 163 TURN 4 T4 LYS 47 ILE 50 TYPE II BEND 3EBX 164 TURN 5 T5 SER 57 CYS 60 TYPE II BEND (DISTORTED) 3EBX 165 SSBOND 1 CYS 3 CYS 24 3EBX 166 SSBOND 2 CYS 17 CYS 41 3EBX 167 SSBOND 3 CYS 43 CYS 54 3EBX 168 SSBOND 4 CYS 55 CYS 60 3EBX 169 SITE 1 RCT 20 TYR 25 LYS 27 TRP 29 ASP 31 3EBX 170 SITE 2 RCT 20 PHE 32 ARG 33 GLY 34 ILE 36 3EBX 171 SITE 3 RCT 20 GLU 38 GLY 40 CYS 41 GLY 42 3EBX 172 SITE 4 RCT 20 CYS 43 PRO 44 VAL 46 LYS 47 3EBX 173 SITE 5 RCT 20 GLY 49 ILE 50 LEU 52 CYS 54 3EBX 174 SITE 1 FNR 4 LYS 27 TRP 29 ARG 33 LYS 47 3EBX 175 SITE 1 CMR 13 CYS 3 PHE 4 CYS 17 CYS 24 3EBX 176 SITE 2 CMR 13 TYR 25 GLY 40 CYS 41 GLY 42 3EBX 177 SITE 3 CMR 13 CYS 43 CYS 54 CYS 55 CYS 60 3EBX 178 SITE 4 CMR 13 ASN 61 3EBX 179 CRYST1 49.940 46.580 21.590 90.00 90.00 90.00 P 21 21 21 4 3EBX 180 ORIGX1 1.000000 0.000000 0.000000 0.00000 3EBX 181 ORIGX2 0.000000 1.000000 0.000000 0.00000 3EBX 182 ORIGX3 0.000000 0.000000 1.000000 0.00000 3EBX 183 SCALE1 0.020024 0.000000 0.000000 0.00000 3EBX 184 SCALE2 0.000000 0.021468 0.000000 0.00000 3EBX 185 SCALE3 0.000000 0.000000 0.046948 0.00000 3EBX 186