IMGT Web resources: IMGT Education

IMGT Web resources

Here you are: IMGT Web resources > IMGT Education > Tutorials > 3D structure

Strand representation of two associated V-DOMAINs

Click here for 3D representation: Mouse (Mus musculus) two associated V-DOMAINs from D1.3Fv

V-DOMAIN
VH, V-BETA or V-DELTA
IGH, TRB or TRD
V-D-J-REGION

Interface between
the 2 V-DOMAINs

V-DOMAIN
V-KAPPA, V-LAMBDA, V-ALPHA, or V-GAMMA
IGK, IGL, TRA or TRG
V-J-REGION

Arrows indicate the direction of the beta strands of the FR-IMGT.
A to G refer to the strand designation in 3D structures.

FR-IMGT

FR-IMGT Length in amino acids Strands (1)

FR1-IMGT 1 to 26 (with 1st-CYS 23) strand A (15)and strand B (11)

FR2-IMGT 39 to 55 (with CONSERVED-TRP 41) strand C (8) and strand C'(9)

FR3-IMGT 66 to 104 (with 2nd-CYS 104) strand C'' (9) and strand D (10)

strand E (12) and strand F (8)

FR4-IMGT from 118 (J-TRP or J-PHE 118) to
the terminal end of J-REGION strand G

(1) Between parentheses the number of amino acids per strand. Amino acids of the AB and CC' beta turns and those of the DE and EF loops are included in the adjacent strands. See Alignments of alleles of the J-REGIONs for the length of strand G.

CDR-IMGT
The maximum length of the CDR1-IMGT (BC loop) is 12 amino acids (positions 27 to 38).
The maximum length of the CDR2-IMGT (C'C'' loop) is 10 amino acids (positions 56 to 65).
The V-DOMAIN CDR3-IMGT (FG loop) length may vary from 2 to 30 or more. However, 80% of the IMGT/LIGM-DB immunoglobulin and T cell receptor rearranged sequences have a CDR3-IMGT less than or equal to 13 amino acids. (Manuel Ruiz and Marie-Paule Lefranc, April 2001)
- Strands facing the inside of the V-DOMAINs are shown in hatching.
- Positions of the 1st-CYS (C23), 2nd-CYS (C104), CONSERVED-TRP (W41), J-TRP or J-PHE (118) are indicated.

Created: 11/06/2001
Last updated: Friday, 22-Sep-2023 18:15:39 CEST
Author: Marie-Paule Lefranc Marie-Paule.Lefranc@igh.cnrs.fr
Editor: Elodie Foulquier

	V-DOMAIN VH, V-BETA or V-DELTA IGH, TRB or TRD V-D-J-REGION
	Interface between the 2 V-DOMAINs
	V-DOMAIN V-KAPPA, V-LAMBDA, V-ALPHA, or V-GAMMA IGK, IGL, TRA or TRG V-J-REGION

FR-IMGT	Length in amino acids	Strands (1)
FR1-IMGT	1 to 26 (with 1st-CYS 23)	strand A (15)and strand B (11)
FR2-IMGT	39 to 55 (with CONSERVED-TRP 41)	strand C (8) and strand C'(9)
FR3-IMGT	66 to 104 (with 2nd-CYS 104)	strand C'' (9) and strand D (10)
FR3-IMGT	66 to 104 (with 2nd-CYS 104)	strand E (12) and strand F (8)
FR4-IMGT	from 118 (J-TRP or J-PHE 118) to the terminal end of J-REGION	strand G