Table 1 Organization of the mouse Ksr gene

The location of exons was determined by analysis of the mouse Ksr gene sequence obtained from the unfinished high-throughput genomic sequence database in GenBank. Clone RP23-240G13, derived from mouse chromosome 11, was found to contain the Ksr gene. The Ksr gene contains 19 exons spanning 4094 nucleotides and coding for 873 amino acids. The exons are differentially spliced so that the KSR1 isoform contains exon 17 but not exon 9a, and the B-KSR1 isoform contains exon 9a but not exon 17.

Exon Nucleotide (size in bp) Codon CA domaina Isoform

1 1–308 (308) 1–75 CA1 KSR1 and B-KSR1
2 309–445 (136) 76–121 CA1 KSR1 and B-KSR1
3 446–597 (151) 122–172 NC KSR1 and B-KSR1
4 598–1019 (421) 173–312 CA2 KSR1 and B-KSR1
5 1020–1083 (63) 313–333 NC KSR1 and B-KSR1
6 1084–1172 (88) 334–363 CA3 KSR1 and B-KSR1
7 1173–1238 (65) 364–385 CA3 KSR1 and B-KSR1
8 1239–1337 (98) 386–418 NC KSR1 and B-KSR1
9 1338–1505 (167) 419–474 CA4 KSR1 and B-KSR1
9a 1506–1547 (41) 14 amino acid insert CA4 B-KSR1 only
10 1506–1607 (99) 475–508 CA4 KSR1 and B-KSR1
11 1608–1992 (384) 509–636 CA5 KSR1 and B-KSR1
12 1993–2087 (94) 637–668 CA5 KSR1 and B-KSR1
13 2089–2224 (135) 669–714 CA5 KSR1 and B-KSR1
14 2225–2354 (129) 715–757 CA5 KSR1 and B-KSR1
15 2355–2492 (137) 758–803 CA5 KSR1 and B-KSR1
16 2493–2625 (132) 804–847 CA5 KSR1 and B-KSR1
17 2626–2839 (213) 848–873 NC KSR1 only
18 2840–2878 (38) None NC KSR1 and B-KSR1
19 2879–4094 (1215) None NC KSR1 and B-KSR1

a CA, conserved area; NC, not conserved.