Low affinity immunoglobulin gamma Fc region receptor II-b

UniProt data

UniProt name: FCG2B_HUMAN (P31994)

Gene name: FCGR2B; Synonyms=CD32, FCG2, IGFR2

Organism: Homo sapiens (Human).

Function: Receptor for the Fc region of complexed or aggregated immunoglobulins gamma. Low affinity receptor. Involved in a variety of effector and regulatory functions such as phagocytosis of immune complexes and modulation of antibody production by B- cells. Binding to this receptor results in down-modulation of previous state of cell activation triggered via antigen receptors on B-cells (BCR), T-cells (TCR) or via another Fc receptor. Isoform IIB1 fails to mediate endocytosis or phagocytosis. Isoform IIB2 does not trigger phagocytosis.

Subcellular location: Cell membrane; Single-pass type I membrane protein.

Transmembrane domains:

  1. 218-240, 23 AA, Helical. {ECO:0000255}.

Sequence: 310 AA

10 20 30 40 50 60 MGILSFLPVL ATESDWADCK SPQPWGHMLL WTAVLFLAPV AGTPAAPPKA VLKLEPQWIN 70 80 90 100 110 120 VLQEDSVTLT CRGTHSPESD SIQWFHNGNL IPTHTQPSYR FKANNNDSGE YTCQTGQTSL 130 140 150 160 170 180 SDPVHLTVLS EWLVLQTPHL EFQEGETIVL RCHSWKDKPL VKVTFFQNGK SKKFSRSDPN 190 200 210 220 230 240 FSIPQANHSH SGDYHCTGNI GYTLYSSKPV TITVQAPSSS PMGIIVAVVT GIAVAAIVAA 250 260 270 280 290 300 VVALIYCRKK RISALPGYPE CREMGETLPE KPANPTNPDE ADKVGAENTI TYSLLMHPDA LEEPDDQNRI

CATM prediction

The sequence of FCG2B_HUMAN returned 4 potential models

The positions at the dimer's interface are highlighted in yellow. The position at the crossing point is highlighted in orange.

# Sequence and interface d θ Z' ω' Score
       220       230       240 
+    |    +    |    +    |   		 (Å) (°) (Å) (°)  
Model 1 QAASSSAMGIIVAVVTGIAVAAIVAAVVA 7.0 -45.9° 2.7 47.3 -22.3
Model 2 QAASSSAMGIIVAVVTGIAVAAIVAAVVA 6.7 -45.8° 2.7 47.0 -18.6
Model 3 QAASSSAMGIIVAVVTGIAVAAIVAAVVA 7.2 -48.7° 2.3 58.5 -6.8
Model 4 QAASSSAMGIIVAVVTGIAVAAIVAAVVA 7.4 -22.2° 3.2 39.9 -0.1
Prolines* QAPSSSPMGIIVAVVTGIAVAAIVAAVVA          

* Note: this sequence contains Pro residues. CATM substituted them with Ala during the modeling. The positions are marked.

Click on the model number to visualize its details below.

MODEL 1 DETAILS

Precited structure:


Click on the image to enlarge

Download model 1 structure: PDB, PyMOL session

List of hydrogen bonds:

Donor Acceptor Distance
B, 228, VAL, HA A, 227, ALA, O 2.91Å
B, 231, GLY, HA1 A, 228, VAL, O 2.86Å
B, 232, ILE, HA A, 231, GLY, O 3.47Å
A, 228, VAL, HA B, 227, ALA, O 2.91Å
A, 231, GLY, HA1 B, 228, VAL, O 2.86Å
A, 232, ILE, HA B, 231, GLY, O 3.47Å