Histo 2

Front 1

Class I molecules

Back 1

Consist of two noncovalently linked polypeptide chains

Front 2

MHC-encoded 44-47 kD α chain (heavychain) Non-MHC encoded 12 kDa subunit called β2-microgIobuIin

Back 2

Chains of Class I molecules

Front 3

5 domains

3 extracellular domains (a1-a3)

transmembrane domain

cytoplasmic domain

Back 3

α chain consists of

Front 4

Peptide binding cleft

Back 4

Produced by interaction of α1 and α2

Front 5

α3

Back 5

Conserved Ig domain

Front 6

β2-microglobulin

Back 6

consists of a single domain and serves to stabilize the structure

Front 7

a3

Back 7

Binding site for CD8+

Front 8

Class 1 molecule

Back 8

A heterotrimer consisting of:

An α chain, β2-microglobulin, a bound antigenic peptide

Front 9

Class I MHC molecules

Back 9

only useful peptide-loaded MHC molecules are expressed on cell surfaces.

Front 10

Class II MHC molecules

Back 10

Composed of two noncovalently associated polypeptide chains:32 to 34 kDa α chain29 to 32 kDa β chain

Front 11

Class II MHC molecules

Back 11

Composed of

32 to 34 kDa α chain 29 to 32 kDa β chain

Front 12

TRUE

Back 12

The genes encoding both chains of class II molecules are polymorphic

Front 13

Peptide binding cleft

Back 13

Interaction of α1 and β1

Front 14

α2 and β2

Back 14

Folded into Ig domain

Nonpolymorphic

Front 15

β2

Back 15

Site for CD4+ attachment

Front 16

Class II MHC Molecules

Back 16

A heterotrimer consisting: α heavy chains, β heavy chains a bound antigenic peptide

Front 17

TRUE

Back 17

Each class I or class II MHC molecule has a single peptide-binding cleft that binds one peptide at a time, but each MHC molecule can bind many different peptides.

Front 18

TRUE

Back 18

The peptides that bind to MHC molecules share structural features that promote this interaction.

Front 19

true

Back 19

The association of antigenic peptides and MHC molecules is a saturable interaction with a very slow off-rate.

Front 20

True

Back 20

MHC molecules cannot discriminate foreign peptides and self-derived peptides

Front 21

noncovalent

Back 21

The binding of peptides to MHC molecules is a ____________ interaction mediated by residues both in the peptides and in the clefts of the MHC molecules