2023/5/2511:22Ramachandranplot-Wikipedia

Ramachandranplot

Inbiochemistry,aRamachandran

plot(alsoknownasaRamaplot,a

Ramachandrandiagramora

[φ,ψ]plot),originallydevelopedin

1963byG.N.Ramachandran,C.

Ramakrishnan,andV.Sasisekharan,[1]

isawaytovisualizeenergetically

allowedregionsforbackbonedihedral

anglesψagainstφofaminoacid

residuesinproteinstructure.The

figureontheleftillustratesthe

definitionoftheφandψbackbone

dihedralangles[2](calledφandφbyOriginalhard-sphere,reduced-

Ramachandran).Theωangleattheradius,andrelaxed-tauφ,ψ

Backbonedihedralpeptidebondisnormally180°,sinceregionsfromRamachandran,with

anglesφandψ(andthepartial-double-bondcharacterupdatedlabelsandaxes

ω).Allthreeangleskeepsthepeptidebondplanar.[3]The

areat180°inthefigureinthetoprightshowsthe

conformationshownallowedφ,ψbackboneconformationalregionsfromtheRamachandranet

al.1963and1968hard-spherecalculations:fullradiusinsolidoutline,

reducedradiusindashed,andrelaxedtau(N-Cα-C)angleindotted

lines.[4]Becausedihedra