There is no pronoun 'our' in Greek. There is just 'us' represented in the genitive form 'of us' which expresses possessiveness or, as in this case, agency - the Agent of salvation.
του μεγαλου θεου και σωτηρος ημων ιησου χριστου [TR]
the great God and saviour of us Jesus Christ [literal - see Green]
The literal translation offered in the body of Green's text is above. In the margin, Green alters this and moves the word 'our' in front of 'great God' for reasons which are not given.
The literal Greek wording supports a very strong expression of the Divine Being and the Divine Power of Jesus Christ, the Divine Saviour of all men, and specially of those who believe (see I Timothy 4:10).
Which is probably why there is reluctance - on the part of some - to translate accurately what is there on the page of the Greek scripture.
EDIT: As commented by @Mac's Musings below, this is an example of the Granville Sharp rule in action where the article 'the' relates to both 'great God' and 'saviour of us' and the two expressions relate to the stated person/noun 'Jesus Christ'.
The whole expression 'the great God and saviour of us' relates to 'Jesus Christ' and semantically uses one definite article to avoid ambiguity.
If Paul had used two articles and had stated (in Greek) 'the great God and the saviour of us Jesus Christ' then there would be ambiguity as to whether two persons were in view. 1. The Great God (The Father) and 2. The saviour of us, Jesus Christ (The Son).
But using one article, Paul clarifies that one person is in view (the Son of God) and this one Person is 'the great God and saviour of us - Jesus Christ'.