CRYSTAL STRUCTURES OF RIBONUCLEASE MS COMPLEXED WITH 3'-GUANYLIC ACID A GP*C ANALOGUE, 2'-DEOXY-2'-FLUOROGUANYLYL-3',5'-CYTIDINE
THE PEPTIDE LINKAGE GLY 53-THR 54 HAS BEEN FOUND TO BE IN THE CIS-CONFORMATION AFTER LEAST-SQUARES REFINEMENT.
Crystal structure of ribonuclease Ms (as a ribonuclease T1 homologue) complexed with a guanylyl-3',5'-cytidine analogue.
Three-Dimensional Structure of Ribonuclease Ms(Asterisk)3'-Guanylic Acid Complex at 2.5A Resolution
Crystallization of a Complex between Ribonuclease Ms and 3'-Guanylic Acid
Three-Dimensional Structure of the Ribonuclease T1(Asterisk)2'-Gmp Complex at 1.9-A Resolution
ESCEYTCGSTCYWSSDVSAAKAKGYSLYESGDTIDDYPHEYHDYEGFDFPVSGTYYEYPIMSDYDVYTGGSPGADRVIFN GDDELAGVITHTGASGDDFVACSSS
SHEET ASP 83 (POSITION 1), GLU 84 (POSITION 2) AND ASN 80 (POSITION X) FORM A "G1 TYPE" BETA BULGE. GLU 84 AND ASN 80 ALSO OCCUPY RESPECTIVELY POSITIONS 0 AND X-1 OF A "WIDE TYPE" BETA BULGE (SEE REMARK 9). ALA 86 (POSITION 1), GLY 87 (POSITION 2) AND ILE 78 (POSITION X) FORM A "CLASSIC TYPE" BETA BULGE. ALA 86 AND ILE 78 ALSO OCCUPY POSITIONS 3 AND X+1 OF A "WIDE TYPE" BETA BULGE (SEE REMARK 9). GLU 4 (POSITION 1), TYR 5 (POSITION 2) AND TYR 12 (POSITION X) FORM A "CLASSIC TYPE" BETA BULGE. GLU 84 (POSITION 0), LEU 85 (POSITION 1) ALA 86 (POSITION 3) ILE 78 (POSITION X-1), PHE 79 (POSITION X) AND ASN 80 (POSITION X+1) FORM A "WIDE TYPE" BETA BULGE (SEE REMARKS 6 AND 7).
THE RMS DEVIATION BETWEEN THE SUPERIMPOSED CA POSITIONS OF RNASE MS AND RNASE T1 (REFERENCE 3, PROTEIN DATA BANK ENTRY 1RNT) EXCLUDING THE FOUR N-TERMINAL RESIDUES IS 0.55 ANGSTROMS. SIGNIFICANT DEVIATION OCCURS ONLY AT THE N-TERMINUS EXCEPT FOR A LOOP-OUT PORTION WHICH INDICATES THAT THE T1 SEQUENCE, GLY 34-SER 35-ASN 36-SER 37, SHOULD BE ALIGNED WITH THE MS SEQUENCE ASP-35-GAP-GAP-ASP 36. THE FOLLOWING CRITERIA WERE ADOPTED FOR ASSIGNING MAIN-CHAIN HYDROGEN BONDS: THE MAXIMUM DISTANCE BETWEEN AN AMIDE HYDROGEN AND A CARBONYL OXYGEN IS 2.60 ANGSTROMS. THE MAXIMUM DISTANCE BETWEEN AN AMIDE NITROGEN AND A CARBONYL OXYGEN IS 3.35.ANGSTROMS. THE MINIMUM NHO ANGLE IS 100 DEGREES. THE MINIMUM COH ANGLE IS 100 DEGREES. THE MINIMUM CON ANGLE IS 100 DEGREES. HYDROGEN ATOM POSITIONS WERE CALCULATED USING THE PROGRAM *X-PLOR*. THE ASSIGNMENT OF BETA-TURN TYPES IS BASED ON WILMOT AND THORNTON (C.M.WILMOT AND J.M.THORNTON, PROTEIN ENGINEERING, 3, 479-493, 1990). PHI,PSI ANGLES ARE ALLOWED TO DEVIATE BY 30 DEGREES FROM THEIR IDEAL VALUES.
RIBONUCLEASE MS (E.C.3.1.4.23) COMPLEXED WITH 3'-GUANYLIC ACID
ESCEYTCGSTCYWSSDVSAAKAKGYSLYESGDTIDDYPHGYHDYEGFDFPVSGTYYEYPIMSDYDVYTGGSPGADRVIFN GDDELAGVITHTGASGDDFVACSSS